Cannot resolve symbol 'Theme' in styles.xml (Android Studio)

Question

Since today, Android Studio can\'t find the AppCompat themes in styles.xml, but for example AppCompatActivity in code does get recognized. My Android Studio version

Answer 1

I encountered this after updating to Android Studio 3.1.

None of the other answers listed here worked for me, however when I switched my appcompat support lib version to the latest 28.0.0-alpha1 then back to 27.1.0 that it was on before, it worked.

Seems the new version of Android Studio lost connection to where the library was synced to and just needed to have it reset.