Android Studio 3.1 Cannot Resolve Symbol (Themes, Widget, attr, etc.)

Question

I upgraded Android Studio today to 3.1, and now Android Studio says it cannot resolve symbols for most of the resources (for example ThemeOverlay in style

Answer 1

Similar error for me when I update to com.android.tools.build:gradle 3.3.1 and gradle-4.10.1

I have tried the following method but didn't work:

1. Clean Project - Rebuild Project
2. Invalidate Caches / Restart
3. Check .xml error (I didn't find any errors about xml )
4. Modify .iml file

I fix this error by modify com.android.tools.build:gradle 3.2.1 and Restart my mac , I didn't know which one can fix it, but it really work for me .