Develop Reference

Unknown Android XML attribute

First, I really dont know wth goin on with android studio ver 3.2.1. I got too much bullshit errors after update this version. Funny thing is i do nothing. After update, everything is fine, but when i restart IDE. everything go wrong.
I tried clear caches, re-install Android Studio, Invalidate Caches, Re-sync project with Gradle, clean project, re-build project. But, nothing change. So, i hope someone can help me. Thanks so much!

Try these:
Method 1:
Delete the .idea folder that is in the project location
Build > Clean Project
Then change something in the app level gradle
Then android studio will ask you to sync the project. Go ahead and sync, the problem will be gone
Credits: https://stackoverflow.com/a/47825463/10471480
Method 2:
Try cleaning up of the following folders:
c:\Users\<user>\.gradle\caches\
c:\Users\<user>\.AndroidStudio3.2\system\caches\

100% Working
Do this two steps:
1.Go to folder where you android studio caches are located. I have android studio 3.6.3 For me it's "C:\Users\Lenovo.AndroidStudio3.6\system\caches"
2.Go to the folder where you android studio projects are located. Open the project >then .idea folder and delete the caches. For me its "C:\Users\Lenovo\AndroidStudioProjects\MyDictionary.idea\caches"

Gradle sync failed: Cause: startup failed (Basic functionality not working)

It is my first time to use android studio V 3.1.3
when i finished installation and trying to build this error is shown
it said that "Basic functioality not working correctly such as building and debugging "
i do not known how to solve it
i use a local gradle distribution like this
Then press on sync project with gradles files
but this error is still shown.
It works well but after that this error is happened
any help
Thanks in advance.

I also have the same problems as you,Now I have solved it.
The following are the steps to be solved
Exit Android Studio.
Delete the .gradle folder eg: C:\Users{userName}}.gradle
Restart androidStudio and wait a moment.

Have you tried
Android studio -> File -> Invalidate Caches/Restart -> Invalidate and Restart

Deleting the .gradle folder was unsuccessfull for me.
Still waiting for another solution.

you should go to settings > build,execution,Deployment > build tool > gradle
and the change the user gradle home that to path of environment variable of JAVA-HOME Address
Like this
and then change gradle JDK to Embedded JDK it will solve your problem

Please configure Android SDK

I am getting this error:
Please configure Android SDK
Onclick of configure i getting one popup

After changing Build Tool Version on the pop screen
26.0.1 changed into 26.0.3 // else selected the highest available version
then click OK started working for me...
(or)
Simply Restart Andoid Studio File->Invalidate Caches and restart

FIX FOR 3.1.2 OR NEWER VERSIONS
I faced the same issue on Android studio 3.1.2, but a simple Sync didn't work for me.The solution was a bit different:
I go to
File -> Invalidate Caches -> Invalidate
File -> Close Project.
Remove the project from the Android Studio project selector window.
Quit from Android Studio(X)
Start Android studio and open project again

I consumed a few hours to fix this issue:
First Click 'Sync' gradle
Then clean and rebuild the application
And invalidate and restart

You can close this project first.
Then DELETE ALL temp file and generated file,
including .gradle, .idea, build in your project's root directory and also build in app path.
Finally, restart your project, problem should be solved. Good Luck !

After executing these two adb commands, it also works fine for me.
(1) adb kill-server
(2) adb start-server

I had the same issue and tried all of the above and it did not help.
I ended up closing everything and rebooting my Mac.
Reopened Android Studio and it was back to normal :)

In build.gradle (Module: app) I changed "compileSdkVersion 23" to 26
Then it works.
Maybe also work for you.

For me solution was to sync project with gradle files.

Gradle project sync failed?

When I started up my project this morning it randomly gave me a message saying Gradle project sync failed. Basic Functionality(eg. editing, debugging) will not work properly. in Android Studio. I looked at other answers that people had put up for this problem but they haven't been working. I invalidated my chaches/restarted my project but no luck. I also deleted my .gradle folder from my project folder and still no luck. If any of you guys could help me that would be awesome! This didn't happen yesterday when I was working on the project or anything, I wonder why its happening now. Oh yea it also says this as a gradle message: Error:C:\Users\Dave\.gradle\caches\2.2.1\scripts\settings_ad4t0wp5ikihzl1y1o83b5sbw\SettingsScript\buildscript\cache.properties (The system cannot find the file specified) :
Thanks again for anyone who reads this/ can help!

There is a file - "cache.properties" that gradle creates for you, upon first time inception of any project. The path for this file is "~Home_Directory\.gradle\2.2.1\taskArtifacts". You may find this path in your home directory. So basically, this file - "cache.properties" is missing from the "taskArtifacts" folder.
One of the solution that worked for me is to copy file - "cache.properties" from any test project of yours to this project that's currently experiencing an issue.
Regards

I had to choose using the Default Gradle Wrapper instead of local.
<< SETTINGS -->/ BUILD TOOLS --> Gradle --> radio button switch... >>
It has helped me to fix the same problem.

I had experience similar sync failed problem with gradle based android project (in Android Studio 1.1.0). I solved this problem without deleting .gradle from my user directory,
steps I followed was
Go to File -> Settings -> Compiler(Gradle Based Android Project)
Change VM options to -Xmx512m -XX:MaxPermSize=512m.
Click Apply -> OK and then tap on Try Again option in sync failed message to clean build the project.
Works like charm!!
UPDATE - 1 : For Android Studio 1.3, Compiler option mentioned in above Step-1 is present inside tab Build, Execution, Deployment.

I had faced similar kind of problem earlier!
But don`t know after rebuild the project and cleaning it, it worked normally.

Invalidate dependency cache by running
gradle clean build --refresh-dependencies
from project root and then re-import your project. Worked for me once.

May be you have put Android Studio into offline mode. To fix it, go to Preferences -> Gradle and ensure that the "Offline work" checkbox is not checked.
Than do
File -> Invalidate caches / Restart
Shutdown Android Studio
Rename/remove .gradle folder in the user home directory
Restart Android Studio let it download all the Gradle stuff it needs
android studio 0.4.2: Gradle project sync failed error

Delete the folder C:\Users\.gradle and reopening the android studio solved my problem

My Android Studio project keeps running my old project/application

I had an Android Studio project I created. The project was named App2-1. After I was done with that project I wanted to move onto my next project named App2-2 that is based off of App2-1. I copied and pasted the directory containing my project "App2-1" and named the new directory "App2-2". Then I opened up the directory using open project in Android Studio. No errors or anything. I made a whole bunch of changes and then I ran the app and it keeps opening my old app. Almost like it has a reference to it or something. Ideas?
Things I've tried:
Restarting Android Studio
Invalidating caches/Restart in AS
Restarted my emulator
Uninstalled my app from emulator/Clean install
Tried a physical device
I'm guessing my workflow of creating a new project based on an old project was incorrect. Appreciate any tips.

I would make a copy of the project in a new folder and in this copy delete the following;
.iml file
.gradle folder
.idea folder
build folder
then open Android Studio and select 'File > Import Project...' and select the new projects settings.gradle file and click 'open'
You might have to check the dependencies and re-build but hopefully this should set things up in AS from scratch.

For me, 'Gradle -> Tasks -> other -> clean' worked.

There might be a new functionality. For me worked:
File -> Invalidate Caches / Restart -> Invalidate and Restart

Tools > AVD manager > click the downward arrow next to your emulator > cold boot now
This should fix all of emulator problems.

For me using AVD Manager -> Actions -> Wipe data made it work.