If above answeres did not work, then you can try my answer because it worked for me.
Here's what worked for me.
- Close Android Studio
- Go to C:\Usersyour username
- Locate the Android Studio settings directory named .AndroidStudioX.X (X.X being the version)
- C:\Users\my_user_name.AndroidStudio4.0\system\caches
- Delete the caches folder and open android studio
This should fix the issue.