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Failed to launch emulator: Error: Emulator didn't connect within 60 seconds

I'm unable to debug using VSCode for Flutter. I'm using Windows and I'm trying to use an Android emulator.
I have attempted to reinstall Flutter, Android SDK and VSCode to fix the issue, as well as tried setting environment variables.
This is the error that I get when launching debug mode.
Failed to launch emulator: Error: Emulator didn't connect within 60 seconds
Are there any better emulators that I can use for both Android and IOS, because I don't even know where to begin with IOS emulators. I'm new to app development and want to get started making applications for both devices.

i had same problem,
i tried to stopping emulator based on Answer of Rahul Shukla:
Steps:
Open Android Studio
Tools -> AVD Manager
Virtual Device -> Actions (Refer Image)
Click On Stop
Now Start Emulator
Now it's working fine :)
but it not work for me.
i test another way. i use these steps:
Open Android Studio Tools -> AVD Manager Virtual Device -> Actions
Click On Wipe data
Now Start Emulator and Enjoy it!!

Steps:
Open Android Studio
Tools -> AVD Manager
Virtual Device -> Actions (Refer Image)
Click On Stop
Now Start Emulator
Now it's working fine :)

Adding the following variables to $HOME/.bash_profile solved my problem
export ANDROID_HOME=$HOME/Library/Android/sdk
export PATH=$PATH:$ANDROID_HOME/emulator
export PATH=$PATH:$ANDROID_HOME/tools
export PATH=$PATH:$ANDROID_HOME/tools/bin
export PATH=$PATH:$ANDROID_HOME/platform-tools

Open Android studio and go to AVD manager.
Click on stop
Click on wipe data
Click Cold boot

I've added a user environment variable:
Name: ANDROID_HOME
Path: Your android folder path, personally it was D:\Android
and restart.
Hope it ll work for you.

For android emulator there are alternatives like geanny motion.
Since you have AVD installed you could try running from the command line.
run flutter devices to get the list of emulators and their id.
then run (assuming emulator-5554 is you emulator id) flutter run -v -d emulator-5554
Finally you the option of starting android studio then start your emulator,form the IDE and the run the above command or you even run the app from the IDE.

For anyone struggling even after trying with the other solutions. Try:
Quit VS Code
Open your terminal and run adb kill-server
Open VS Code again and attempt to run your app on your emulator.

This is what worked for me. In Android Studio, go to Settings, and select HAXM.
Then go to Tools, AVD Manager, and click on the Play button to start your emulator.
Also, make sure you have enabled Hardware Acceleration in your BIOS, if you have not done so yet. Check this post for this matter:
Error during installing HAXM, VT-X not working

Approach of wiping data listed above worked for me , i mentioned those in steps :-
Steps:
1.Open Android Studio
2.Tools -> AVD Manager
3.Virtual Device -> Actions
4.Click On wipe data
5.Now Start Emulator
6.Now restart the pc
Restarting the pc is not necessary i just did it as a follow-up,
although make sure your android studio is updated because in my case AS was not updated so i think my emulator was not working and VS Code was throwing errors .

Try restarting your PC once! It worked for me!

I had the same issue on Linux. I resolved it by disabling hardware acceleration for the emulator:
Android Studio -> AVD Manager -> Edit emulator -> Emulated Performance: Changed from Hardware to Software.
Update:
It turns out that while Flutter is unable to launch emulators with hardware acceleration, they launch with acceleration just fine from Android Studio or with the emulator command.
As of April 2020 you can override emulator launch commands for Flutter in VS Code.
In VS Code settings you can search for dart.flutterCustomEmulators, or directly populate your settings.json like so:
You can get the emulator ID with the flutter emulators command:
Now when you choose this emulator in VS Code it will use the emulator command from the Android SDK rather than the flutter emulator command it usually uses, and it launches and connects successfully as expected.

Here are the reasons I had
Out of disk space.
Android Studio didn't launch. I immediately started looking for the problem in VS.

You can try to wipe the data of the particular device.
Go to -> Android Studio -> Tools -> AVD Manager -> [Select the down triangle on your chosen device] -> Wipe data.
Now retry.

I am using Genymotion 3.0.2., VS Code (version 1.36.1)
You can read about it here - Using Genymotion Emulator with Flutter in VS Code — (Without Android Studio)
Open up Genymotion and go to the ADB Setting section:
Notice how the default selection is “Use Genymotion Android Tools (default)”? With this selection, the emulator is not recognized.
Change it to “Use custom Android SDK tools”, set the SDK location to where your SDK is (in my case it’s at “C:\Program Files (x86)\Android\android-sdk”). Make sure the tick mark (“This folder is valid”) is displayed.
Close the settings box.
Now reload your “VS Code” IDE.

The problem for me was that Intel HAXM wasn't installed. When I opened AVD Manager through Android Studio and tried to launch the emulator from there (instead of trying through VS Code), it told me that HAXM was required and prompted me to install it. After Android Studio installed HAXM successfully, I could run the emulator from VS Code without any issues.

Just restart the PC, works every time. It is that simple.

Check if it already running. Find qemu-system-x86_64 (or similar) on windows task manager, choose end task. Try launch it again.

Make sure that vt-x is enabled in your bios

For me "wipe data" by going into :
Android Studio
Configure
AVD Manager
Wipe Data
Didn't work.
So I did it the hard way :
Delete the emulator
Create a new one.
You should increase the internal memory of your device.

You need to first install android studio.
Follow these steps (Works for Android Studio 3.5.1)
Choose "Run" in the top menu bar
Press on "Select Device"
Select "AVD manager"
There will be a popup now for creating your virtual device.

For me, it was "Not enough disk space". Generally, in these situations, you can run Android studio then Tools-> AVD manager and start manually.
If there is a issue then you can see the actual in android studio logs.

Mine was similar but for iOS and it said Failed to launch iOS Simulator: Error: Emulator didn't connect within 60 seconds . I closed all instances of VS Code, opened the project again and this time it worked.

I also had the same problem above when i freshly install AVD API28. I tried all posted solutions in this thread and they didn't work for me.
So, I go to android studio --> AVD manager --> Click the green play button(Launch this AVD in the emulator).
then VSCode can detect the emulator and it works fine.
But, I think it will need to run AVD manually every time we wants to use the emulator.

I am encountering the same problem with the emulator that it is not starting and says:
"Emulator didn't connect"
Solution:
Make sure that your virtual technology (Vf-x) is enabled in the bios
setting.
This solves my problem.

For me, this was happening quite often and cleaning cache was a bit hectic for me as I had to download few files again and again.
What I did was, stopped the AVD from Android Studio
Then, I ran flutter run from VS-Code and it worked!

delete AVD and create a new one worked for me.

For some, it might be problem of the emulator and Android API itself.
A duplication of the problem mention in Can launch, but not connect, to emulator in VS Code and Android Studio using flutter.
I sort it using a API 29 instead of 30. Since API 30 (in Pixel 4) skipped the allow debug mode.
Hope it helps for some of you.

It was a storage issue for me. Had to clear up space by deleting junk files and I was able to restart my emulator.

I am using Lenovo V15 laptop.
I chose extreme performance from bios settings. And I encountered this error.
When I select intelligent cooling, the problem was solved.
In a nutshell,
Replace 'extreme performance' with 'intelligent cooling' in the bios.

Follow these steps:
Find qemu-system-x86_64on Task Manager and end task
Open cmd and execute this command adb kill-server
It works for me. Good luck

waiting for device to come online

A couple of days ago (15th April 2017) I updated Android Studio with all the latest updates. Now when I try to run an app, the emulator window opens but I just get a message "waiting for device to come online". Eventually this times out and I get a message "installing APK", where it just seems to get stuck. I have searched the site and tried various advice including:
Deleting all the emulators and re-creating
Turning off the emulator in SDK manager, re-starting Android Studio and turning the emulator on again
turning off instant run
re-booting my PC, in case some update needed a re-start
The emulator I have is Nexus5X API23.5554
I have also deleted my app and created a completely new "hello World" app that does nothing but display one line of text, but I still get the same problem.
Has anyone any other ideas?

I ran into this issue too. It seems to be a bug with recent changes to the Android emulator. There is a workaround:
Launch the emulator independently from the Android Virtual Device (AVD) manager (there's an icon in the main Android Studio window)
Run your app. You'll notice the device name has changed from whatever the emulator is called to some generic name like 'Android x86 API 25'.
The app will run correctly on the emulator. You'll notice in logcat that the device name is 'emulator unknown'.
Hopefully Google will fix this over the next few days.

I couldn't get any emulator going at all, with no error messages, just 'waiting for device to come online'.
When tried to stop and start adb.exe in terminal:
adb kill-server
adb start-server
it said that adb is outdated. I had latest adb version downloded but Android Studio was trying to use some other file which was older version.
Finally, I checked environment variables and removed paths to:
C:\NVPACK\android-sdk-windows\platform-tools
and
C:\NVPACK\android-sdk-windows
as the newest version of SDK platform-tools I had on drive E: not C:, and is all working now.

Enzokie - Thanks. Nothing there seems to work, though. As a novice, I always assume that if something is wrong, it's my fault, but maybe not this time! I shall do as you suggest and raise it with Android unless anyone else suggests something that works.

My work around was to use a Nexus 5 instead of Nexus 5X.
If you don't know how to make an new emulator its tools>android>AVD manager> create new virtual device. Then just pick a new emulator and hit next until you're finished or customize it.

Resetting the ADB did the trick for me.
For Mac, In Android Studio -> Tools -> Android -> Android Device Monitor -> Under devices -> Down arrow there will be reset ADB option.

What worked for me was to wipe the emulator data. You can do this from AVD manager:
Tools -> AVD Manager -> Right click on virtual device - > Wipe Data

Hi I had the same Problem...so I did this:
Start your emulator, you will get the "wating for device to come online" error msg.
Wait till the emulator boots, then stop the process.
Now, on the emulator go to settings and make your "device" (emulator) to a developer device.
Check this, if you dont know how to do it -> https://www.digitaltrends.com/mobile/how-to-get-developer-options-on-android/
Then go on "Developer options" (in settings) and switch on the "usb-debugging" option. Remeber you PCs fingerprint.
Hope this was helpfull....

Waiting for Target Device to Come Online

I recently updated to Android Studio 2.3, and now when I try to run the application, the emulator does not come online. It times out after 300 seconds.
Additionally, The app has been experiencing a FATAL EXCEPTION ERROR (OOM), and I am not sure how to fix that either, or if that is part of the emulator problem.
Any help is much appreciated. Again, my knowledge in the program is very limited so if your answer can be kept simple, that would be great.

Following worked for me on Android Studio 3.x.
Step 1:
Open AVD Manager.
Step 2:
Right click and Wipe data for the virtual device you're testing on.

I too had the same problem, then I went to AVD manager and right click on the emulator and stopped it and I RUN the application again and this time it worked.
It may be a temporary solution but works for the time being.
Tools -> AVD manager -> right-click on the emulator you are using -> Stop
Now Run your application again.
Note: Sometimes closing the emulator directly is not working for the above-mentioned problem but stopping it from the AVD manager as mentioned is working.

In case you are on Mac, ensure that you exit Docker for Mac. This worked for me.

Three days on this, and I believe there's a race condition between adb and the emulator. On a request to run an app, with no emulator already running, you see the "Initializing ADB", then the emulator choice, it starts and you get "Waiting for target to come online". An adb kill-server, or a kill -9, or an "End Process" of adb with the task manager will cause adb to die, restart, your APK installs and you're good to go. It does seem funky to me that an "adb kill-server" causes adb to die and then restart here, but that's another mystery, maybe.

Another case is Android Emulator should be reinstalled. This can happen, when you install a higher version of Android Studio, then update SDK for it, and go back to previous one.
Tools - Android - SDK Manager - SDK Tools - Android Emulator -
uncheck, apply, check, apply
Disable Docker app if you have it (Mac users).
Restart emulator:
Tools - Android - AVD Manager
(or kill adb process in task manager).

Go to AVD Manager in your Android Studio.Right Click on your emulator,and then select wipe data.Then run your app again.
The emulator will perform a clean boot and then install your apk then your app will finally run.
Summary:AVD Manager---Right Click Emulator----Wipe Data----Run App Again
If the problem presists,then simply go back to your avd manager ,uninstall emulator,then add a new emulator.Once the new emulator is added,in your avd manager,run the emulator...Then run your app.
Its much simpler if you have an emulator already running from the onset before running your application for the first time

After trying all these solutions without success the one that fixed my problem was simply changing the Graphics configuration for the virtual device from Auto to Software (tried hardware first without success)

This solution works for me :
Tools -> AVD Manager -> click drop down arrow -> select Cold Boot Now

Below steps work for me
Close running emulator
Go to AVD Manager
Choose available emulator
In that action tab (last one), click on drop down arrow & select COLD BOOT NOW
Finally run your application

Seems like Android Studio (using version 3.5.1) gets into a weird state after a while. This worked for me.
File -> Invalidate Caches / Restart -> Invalidate and Restart

Go to AVD Manager right click on your device and select Wipe Data and Cold Boot Now.
For me it worked correctly.

After trying almost all the solutions listed above, what finally worked for me was to create a new virtual device using a "Google APIs" image instead of a "Google Play" image.

Seems that in my case the problem was in that the "Google APIs ARM EABI v7a System Image" wasn't automatically installed during installation of Android Studio.
After installing the image, the emulator began to work.
Screenshot of the SDK manager

Did not read all the answers. Anyway Accepted one didn't work for me. What did was upgrading the android studio to last stable version and then created a new virtual device. I guess my nexus 5p virtual device got out of sync with the android studio environment.

This worked for me on Android studio 4+ and Mac OS
Delete all AVD's that you currently have.
Go to Preferences > Appearance & Behavior > System Settings >
Android SDK > SDK Tools
Uninstall Android Emulator
Restart Android Studio.
Re-install Android Emulator from the same place.
Create a new emulator!

I discovered that having a running instance of Docker on my machine (OSX) prevented the Android Emulator from running (see Android Studio Unable to run AVD)
Previously, my emulator would appear to start, then fail before any device window was shown.
I also had to use 'kill -9' (as per #MarkDubya ) to get Android Studio to connect to the virtual device.

Like urupvog's answer, make sure that you aren't running any other virtual machines like VirtualBox. When I restarted my computer, AVD worked until I started Vagrant for backend development (then it wouldn't launch).
See Android emulator and virtualbox cannot run at same time for more info.

Check you don't have the deviced unauthorized, unauthorized devices reply the same error in the Android Studio, check the emulator once is on with the adb command.
$ adb devices
List of devices attached
emulator-5554 unauthorized
If you have of this way the emulator the Android Studio is waiting for be authorized and maybe this can solve the problem.
Authorized Devices
This is a error I have solved in Windows 10 with Android Studio 2.3.3

Fix for this issue is simple :
Go to SDK tools > SDK Tools
Check Android Emulator and click Apply
and sometimes you might see there's an update available next to it, you just need to let it finish the update

For those stuck on this problem on a device and not the emulator, make sure your app isn't set as the device owner.

Question is too old but may be helpful to someone in future.
After search many things, most of them is not worked for me. SO, as per my try This solution is worked for me. In short uninstall and install "Android SDK Tools" in Android SDK.
Few steps for that are below:-
go to "SDK Manager" in Android Studio
go to "SDK Tools" tab
Uninstall "Android SDK Tools" (means remove check(uncheck) ahead of "Android SDK Tools" and Apply then OK)
Close and Restart Android Studio
Install "Android SDK Tools" (means check ahead of "Android SDK Tools" and Apply then OK)
Image of Uninstall and Install Android SDK Tools again

The problem is that there is no link between ide and the emulator.
In our case - we lowered version of android for the app, that frustrated ide in emulator linking.
If we install Android 25 and bind project to it, and AVD Device on Android 25 as well - it links and apllies changes on the fly. If we downgrade to Android 14 and device on android 14 - it doesn't.
Used Android Studio 2.3.
To play with versions you can set in Gradle Scripts - build.gradle (Module: app):
android {
compileSdkVersion 25
defaultConfig {
minSdkVersion 15
targetSdkVersion 15
}
}
As a result app won't run on an Android 25 device with a message:
Installation failed with message Failed to finalize session : -26:
Package ru.asv.test new target SDK 15 doesn't support runtime
permissions but the old target SDK 25 does.. It is possible that this
issue is resolved by uninstalling an existing version of the apk if it
is present, and then re-installing.
WARNING: Uninstalling will remove the application data!

I also ran into this problem and probably found the solution that may help. The key is launching the AVD in the emulator first then run your App.
Following are the steps:
In the Your Virtual Devices screen, select the device you just created and click Launch this AVD in the emulator
Once the emulator is booted up, click the app module in the Project window and then select Run → Run
In the Select Deployment Target window, select the emulator and click OK.

For Linux users using KVM and facing this problem try setting the Graphics option on the Android Virtual Device to Software instead of Automatic or Hardware . As previously mentioned in this answer.
I can confirm that the method works for Arch Linux, Ubuntu 16.04, as well as windows with or without a proprietary graphics card using Android Studio version 2.3.1+

I am working on notebook, Windows 8. I solved this issue change mode from battery saving mode to balanced mode. Before that, an emulator didn't work and I see "Target Device to Come Online". Also didn't work Genymotion

I had a similar problem when updated my android studio. Somehow it changed my SDK path. I just changed it to my updated SDK path and it worked.
Android Studio -> File -> Settings -> Appearance & Behaviour -> System Settings -> Android SDK
Here you will find Android SDK location just click on edit link in front of that and browse and select the Android SDK from the file browser. Select and click on Apply.
Select AVD manager and start Emulator. This solution worked for me.

Go to terminal and type android avd. Select your AVD and select "Edit". Make sure you do not see No CPU/ABI system image available for this target - it will show in red font at the bottom. Change the target to the one that is available or download the ABI image. Sometimes, if you create an AVD from inside Android Studio, it does not ensure this requirement.

None of solutions above worked for me, so I had to wipe content of
C:\Users\your_name\.android\avd
and re-create emulated device

I've had the same problem (AVD not coming online) in a Linux system. In my case, I have solved it setting this environment variable:
$ export ANDROID_EMULATOR_USE_SYSTEM_LIBS = 1
This case is documented here: https://developer.android.com/studio/command-line/variables.html#studio_jdk

Finally, I solve this problem by setting the right export path in bash file:
export ANDROID_HOME=/Users/[username]/Library/Android/sdk

Android studio: emulator is running but not showing up in Run App "choose a running device"

I have launched my emulator via the AVD manager and once it's running I have clicked on run app. I have waited a couple of minutes for my running device to show up in choose a running device but the window always stays blank.

Probably the project you are running is not compatible (API version/Hardware requirements) with the emulator settings. Check in your build.gradle file if the targetSDK and minimumSdk version is lower or equal to the sdk version of your Emulator.
You should also uncheck Tools > Android > Enable ADB Integration
If your case is different then restart your Android Studio and run the emulator again.

This thread helped me to solve my problem, in particular this answer:
In Android Studio go to Menu -> Tools
Android
Uncheck Enable ADB Integration

Had similar issue with my emulator.
Solved by Wiping Data of emulator
Tool > ABD Manager > Down arrow under Action Wipe Data
Note : This is remove all data inside emulator.

For anyone else having the issue - none of the answers provided worked for me.
My case may be different to others but I had Android Studio installed first which installs the SDK by default to: C:\Users\[user]\AppData\Local\Android\sdk. We then decided to use Xamarin for our projects, so Xamarin was installed and installed an additional SDK by default, located here: C:\Program Files (x86)\Android\android-sdk.
Changing Xamarin to match the same SDK path worked for me which I did in the registry (although through the VS settings I'd guess it's the same):
\HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Android SDK Tools\Path
Change the path to match the Android Studio SDK path, close everything, start the VS Emulator, run Android Studio, ensure ADB integration is off and try. It worked for me.

If you uncheck the ADB Integration, you cannot use the debug any more.You may just restart the adb server, run
$adb kill-server
$adb start-server
in Terminal to restart the adb server without restarting the Android Studio. Then the emulator shows up.

My emulator used to suddenly disappear but the app still continues to run.
Solution-
Open task manager and kill qemu-system (Under Android Studio). This will stop the emulator. Then restart emulator.

Your adb connection is broken.
close eclipse
open cmd-prompt type adb kill-server then adb start-server
reopen eclipse
run the project!

Wipe the data of your Android virtual Device and then start the emulator. Works for me.

I had the same issue on a brand new computer, and the reason was simple. Although I downloaded and unzipped the Android SDK, I didn't add it to the PATH. So:
On Windows, you have to launch envvar and there, add the path to your android/platform-tools
On MacOS, edit the .zshrc file in your home, and add
export PATH="$PATH:/your/own/path/to/android/platform-tools"

This answer is not proposing a solution. Just a workaround in case someone is looking
I am using Idea based Android Studio (some people are talking about eclipse one here)
When I launch the app in the emulator (using the Run App button of Android Studio) AVD shows up but the app does not launch or run.
However when I connect my mobile and launch the app on my mobile the App works (this itself took some time, enabling developer options on mobile and doing the right configuration)
Because My app is launching on connected mobile, I can say nothing wrong with App.
There is some problem with AVD integration which I could not figure out so As of now I am working around my problem following way.
1 - I installed the app manually by dragging the APK file on AVD. (APK file is app\build\outputs\apk\debug folder)
2 - Then my AVD was not showing the installed APP list.
3 - I searched my APP using Google bar on AVD and dragged the APP icon on the home screen of AVD.
4 - I can now launch the APP using my APP icon on the home screen of AVD.
**That's how I am working around my problem. **
I have verified that Run App Icon does install the Application. Installation, not launching, appears to be the problem for me.

try to open the emulator and run it parallel with android studio/eclipse and the option will be displayed to select in the choose the device(emuator name, mine is Genymotion).

Check the android path of the emulator.
I had to change the registry in here:
HKEY_LOCAL_MACHINE > SOFTWARE > WOW6432Node > Android SDK Tools
to the actual path of the sdk location (which can be found in android studio: settings-> System Settings -> Android SDK)
All the credit goes to the author of this blogpost www.clearlyagileinc.com/

start device from genymotion button (have to install genymotion before and setup genymotion folder location on settings)
run application
choose genymotion running device

in your device you want to run app on
Go to settings
About device >> Build number triple clicks or more
and back to settings you will found "Developer options" appear
go to and click on "USB debugging"
Done

Android Studio doesn't see genymotion

I updated 0.5 to 0.8.14 version of android studio , but now studio doesn't see genymotion , what I must do now ? Thanks for all .
Edit :I solved the problem by updating genymotion too

Genymotion by default uses it's own ADB binary. If it has a different version than the one Android Studio is using, they can conflict and you get lots of issues. One of them can be Genymotion not being detected, and problems deploying apps.
I would recommend setting Genymotion to use the ADB/Android SDK that Android Studio is also using, instead of using the default one. That way you will avoid conflicts on future updates.

You MUST install the plug-in for Genymotion first, click the "File" tab locate the "Plug-in" option, down the bottom, search for Genymotion, then install. After the installation, you need to restart Android Studio, after that, you will see the Genymotion icon near the "Sdk Manager" icon, click on it, then just specify the location of your Genymotion installation. Also, make sure you have "Oracle Virtual Box" installed in order to use Genymotion, it is a requirement.
Edit-
Then your genymotion virtual machines come up, click the one you want (I think it has to be off for start to be clickable/not greyed) then click start,
then click that green Play icon near the centre of the button bar below the menu bar, then the genymotion virtual machine should appear listed under 'running devices'. highlight it and click ok, and it should launch and show your program.

Open Genymotion Shell,use command line devices list will show the then in cmd use command line adb connect IP address.if not show devices in studio.maybe restart studio.

One words(you need find your devices ip):
adb connect 192.168.***.***:5555
2019-03-19 09:10:00
My enviroment：
Ubuntu 18.04
Genymotion Version 3.0.1
Android Debug Bridge version 1.0.40
AndroidStudio version 3.3.2
My problem:
adb devices : list is empty
no usb devices or running emulators detected
My solution :
cd /opt/genymobile/genymotion
./genymotion-shell
devices list (if no running devices start one)
in other terminal run commond : adb connect yourDeviceIP:5555
Reference:
https://stackoverflow.com/a/27262302/7707781
https://stackoverflow.com/a/24926960/7707781

I had the same problem, I close genymotion, then clicked on Run button , so the "Select Deploymnt Target" dialog opened. after that I open genymotion as administrator, start virtual device and after a minute it appear in "Select Deploymnt Target" dialog.
I think the key point is that genymotion has to be run after android studio, and maybe with "Select Deploymnt Target" dialog has to be opened!
It works for me anyway

After few research I found a solution, open task bar and just End Process the adb.exe, hit run (android studio) and adb will be recreated and your genymotion emulator will be on the list. Thumbs up

When I updated Android Studio to 3.4, same problem is occured in my system.
Open Genymotion program,
Click "Genymotion" text on the upper left corner,
"Settings" --> "ADB" --> check "Use Genymotion Android Tools (default)"
Restart Genymotion program.

Go to Genymotion → Setting → ADB → Use Custom Android SDK tools
(C:\Users\{username}\AppData\Local\Android\Sdk).
Go to Android Studio → Search for "Genymotion Device Manager" → Specific the part for Genymotion (C:\Program Files\Genymobile\Genymotion).
Go to Android Studio → View → Appearent → Toolbar.

first install genymotion plugin and restart and android studio.After the restart you will see genymotion device manager icon near sdk manager icon select it and add the path where u have genymotion folder.If u didn't see the icon then search for genymotion device manager u will get it

I have faced this problem once. I must connect it to adb server manually and it worked fine!
just follow these steps:
1- open your emulator
2- after running, open oracle vm virualBox manager app
3- double click on your running emulator. you will see Ip management value. that's the emulator local ip address
4- go to your sdk manager path, then platform-tools directory
5- open cmd on this directory (or use cd command)
6- run adb connet ipAddress:5555
after that you will see connected to ip address text on the screen. go back to android studio and you see adb has appeared!