I installed android studio for the first time on windows 7 and i got this error:
Gradle 'MyApplication5' project refresh failed Error:Unexpected lock protocol found in lock file. Expected 3, found 0
Try deleting the .gradle folder in your project and restart Android Studio.
In android studio, click "File" , then click "Invalidate Caches / Reload" and confirm. if that doesn't solve the problem, remove the .gradle file from the project file and restart Android Studio .