Develop Reference

Android emulator suddenly stopped to work

I am developing an app on Visual Studio with Xamarin. Yesterday emulator was working fine but it stopped to work suddenly without no reason.
Here is error message from vs console:
Starting emulator my_device ...
C:\Program Files (x86)\Android\android-sdk\emulator\emulator.EXE -partition-size 512 -no-boot-anim -avd my_device -prop monodroid.avdname=my_device
Failed to open /qemu.conf, err: 2
HAX is working and emulator runs in fast virt mode.
C:\Program Files (x86)\Android\android-sdk\emulator\qemu\windows-x86_64\qemu-system-i386.exe: error while loading state for instance 0x0 of device 'goldfish_pipe'
deleteSnapshot: for default_boot
emulator: INFO: QtLogger.cpp:68: Critical: UpdateLayeredWindowIndirect failed for ptDst=(1113, 122), size=(300x21), dirty=(300x21 0, 0) (Sisteme bağlı bir aygıt çalışmıyor.) ((null):0, (null))

Go to AVD manager
Try Wipe Data or Cold Boot Now options.

Most of the times, this error is caused when the system tries to draw something like app borders/edges etc and when it fails, it throws following error of UpdateLayeredWindowIndirect Failed
Therefore, it is highly related to graphics, so, try changing your Emulated Graphics in
AVD configuration --> Emulated Performance --> Graphics: Software
Please note that if you are using Google PlayStore API for Android SDK then you might not be able change this setting, therefore, if you are unable to change option of Graphics to Software, please create virtual device without PlayStore

Emulator: emulator: ERROR: x86_64 emulation currently requires hardware acceleration

When I try to run my Hello application , the emulator gives this message. What is the sulotion?
This is the emulator view unfortunately.
Error
31/08/2018
16:32 Gradle sync started
16:32 Project setup started
16:32 Gradle sync finished in 3s 187ms (from cached state)
16:34 IDE and Plugin Updates: Android Studio is ready to update.
16:35 * daemon not running; starting now at tcp:5037
16:35 * daemon started successfully
16:35 Executing tasks: [:app:assembleDebug]
16:35 Emulator: emulator: ERROR: x86_64 emulation currently requires
hardware acceleration!
16:35 Emulator: Process finished with exit code 1
16:35 Gradle build finished in 27s 847ms

Boot into bios and enable VTX. This allows the emulator to use hardware virtualization.

As can be seen in your error-output, running an emulator x86_64 emulation currently requires hardware acceleration!.
What does this error mean/where does it come from?
Emulations run in a virtualized thread of your CPU. A CPU normaly got several physical cores (e.g. in QuadCore CPUs there are 4 physical cores). Virtualization furthermore subdivides these cores into multiple "virtual" cores, meaning it simulates more phyisical cores. You can read more information elsewhere on the internet. Here an extract from geek-university which sums it up pretty short to the point:
CPU virtualization involves a single CPU acting as if it were multiple
separate CPUs. The most common reason for doing this is to run multiple different operating systems on one machine. CPU
virtualization emphasizes performance and runs directly on the
available CPUs whenever possible. The underlying physical resources
are used whenever possible and the virtualization layer runs
instructions only as needed to make virtual machines operate as if
they were running directly on a physical machine.
When many virtual machines are running [...], those [...]
might compete for CPU resources. [...].
Emulators need this environment due to the highlighted reason: Its emulating an entire other system - In your case an Android smartphone.
Solution
Regarding you have an Intel-CPU (AMD should be somehow analog), this should solve your problem.
As general note (this seems to be solved in OPs question since its not in the error log): Make sure Intel x86 Emulator Accelerator (HAXM installer) is installed in your Android SDK (check under Settings -> Appearance & Behavior -> System Settings -> Android SDK -> SDK Tools)
Also as note if somebody wants to check if he has OPs problem coming from a more generic error: Run this command in the command line (needs Android SDK Command-line Tools (latest) to be installed in your SDK):
C:\Android\YourApp> C:\Users\{Username}\AppData\Local\Android\Sdk\emulator\emulator.exe -avd YourAVDName -netspeed full -netdelay none
# The First is your path to your SDKs emulator.exe; use the path you installed the SDK in
# -avd needs a name of an existing AVD you set up in the AVD Manager in Android Studio.
The possible outcome is (if HAXM is already installed and hardware acceleration is your poblem):
emulator: Android emulator version 30.5.3.0 (build_id 7196367)
(CL:N/A) handleCpuAcceleration: feature check for hvf emulator: ERROR:
x86_64 emulation currently requires hardware acceleration! CPU
acceleration status: VT feature disabled in BIOS/UEFI More info on
configuring VM acceleration on Windows:
https://developer.android.com/studio/run/emulator-acceleration#vm-windows
General information on acceleration:
https://developer.android.com/studio/run/emulator-acceleration.
Note that I used an AVD with x86_64 here.
To solve the error you have to restart your PC and enter your BIOS. Search for you CPU-preferences (can often be found in an Advanced-options tab). Somewhere there you'll find a setting called Intel Virtualization Technology which presumably is disabled. enable and restart your computer.
Now your AVD should work fine.

Cordova black screen cold boot

I am trying to run "cordova emulate android" on the default hello cordova project, however when I run it I get an alert saying "cold boot: snapshot doesn't exist", and the emulator screen simply stays black. Here is the terminal output:
BUILD SUCCESSFUL in 3s
47 actionable tasks: 1 executed, 46 up-to-date
Built the following apk(s):
/home/marc/Documents/Tests/cordova/hello/platforms/android/app/build/outputs/apk/debug/app-debug.apk
ANDROID_HOME=/home/marc/Android/Sdk
JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
No emulator specified, defaulting to test
Waiting for emulator to start...
emulator: Requested console port 5584: Inferring adb port 5585.
emulator: WARNING: Host CPU is missing the following feature(s) required for x86 emulation: SSSE3
Hardware-accelerated emulation may not work properly!
emulator: WARNING: Not all modern X86 virtualization features supported, which introduces problems with slowdown when running Android on multicore vCPUs. Setting AVD to run with 1 vCPU core only.
warning: host doesn't support requested feature: CPUID.01H:ECX.ssse3 [bit 9]
emulator: WARNING: Not saving state: emulator hasn't finished booting.
How can I fix this?
P.S. I am using andorid api version 26 on Ubuntu 16.04.3 LTS

I answered a question similar to this here. Quickly: The issue might be your CPU hardware. Certain AVD Google API levels do not run well on CPUs that do not support certain features; in your case 'SSSE3'. Try an older AVD Google API level <= 20.

Android Emulator is not running (Error)

Android emulator is not running and is showing this error:
D:\Software\tools\emulator.exe -netdelay none -netspeed full -avd
Nexus_4_API_23 emulator: device fd:748 HAXM is working and emulator
runs in fast virt mode emulator: Failed to sync vcpu reg emulator:
Failed to sync HAX vcpu context Error accepting connection, aborting

just shut down all virtual boxes. Most people have genymotion running which causes the issue. run one emulator at a time and virtual device.

I think that you need to install the HAXM on your machine. To do so just follow the path
Your SDK\extras\intel\Hardware_Accelerated_Execution_Manager
there you can install the intelhaxm-android. if its giving you the error thats mean your machine has turnd off support virtualization or does not support. For understanding this and how to work around to enable this I would suggest you read this little discussion

unable to launch android emulator due to error in installing intelhaxm

I m getting the following error when i start my emulator
Starting emulator for AVD 'MyAVD'
emulator: ERROR: x86 emulation currently requires hardware acceleration!
Please ensure Intel HAXM is properly installed and usable.
CPU acceleration status: HAX kernel module is not installed!
I downloaded the intelhaxm and m trying to run the application file so it shows "VT not supported"
then i went to cmd and tried dism.exe /Online /Disable-Feature:Microsoft-Hyper-V
but i got the following error
Deployment Image Servicing and Management tool
Version: 6.1.7600.16385
Image Version: 6.1.7601.18489
Error: 0x800f080c
Feature name Microsoft-Hyper-V is unknown.
A Windows feature name was not recognized.
Use the /Get-Features option to find the name of the feature in the image and tr
y the command again.
The DISM log file can be found at C:\Windows\Logs\DISM\dism.log
i tried disabling hyperv from control panel--programs and features but it is not listed there
please help

I had the same problem and resolved it. Make sure you have enabled hardware virtualization in your BIOS, should be under CPU Configuration. Once I had that enabled, the haxm installer ran without any problems. As for Microsoft-Hyper-V, it doesn't seem to be a feature (leastwise it's not listed) so I don't know what's up with that.