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

In newer versions of Android Studio, we are asked to use 'AppCompat'. Some users uncheck that and still use the Theme.AppCompat. That makes up this error. Same happened with me.

Solution is to add this line in your build.gradle (app).

compile 'com.android.support:appcompat-v7:26.1.0'