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

EDIT: As @Alexey noted, bug still appears in Android Studio v3.1.4

This worked for me:

• Click File > Close Project
• Reopen the project from Studio's dialog.

Answer 2

you can hit file -> invalidate Caches / Restart ... if it doesn't fix the issue you can close the project (file-> close project) and import it (file -> new -> import project.

Answer 3

I ran into the same problem when updating the Android Studio software. What I did was this:

Go to the Gradle Settings as follows (this path is for Mac, but should be similar on Windows):

Android Studio -> Preferences -> Build, Execution, Deployment -> Gradle.

Then pick "Use default gradle wrapper (recommended)".

If you already have that option chosen then your problem must lie somewhere else.

Answer 4

No need to change anything.

Just press small button on top "Sync Project with Gradle Files"

Answer 5

@Daniel Wilson made a comment in one of the answers that solved this issue for me. I wanted to add add as an answer to draw more attention to this solution.

Updating compileSdkVersion and targetSdkVersion from 26 to 27 (and then of course updating the dependencies) eliminated the errors for me.

Answer 6

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.