Android Studio says "cannot resolve symbol" but project compiles

Question

I'm importing twitter4j in AndroidStudio, using the following in my build.gradle:

dependencies {
  compile 'com.android.support:support-v4:18.0.+'
  compile files('libs/twitter4j-core-3.0.4.jar')
}

The project compiles fine, and I can create twitter objects without a problem. However, in Android studio, anything referencing that library shows "cannot resolve symbol" and displays in red. What do I need to do to get Android Studio to recognize the library?

I have already tried rebuilding the project, ./gradlew clean, and closing and re-opening my project.

Answer 1

No idea if this will work or not but my only thought so far: right click the jar file in file tree within AS and select "Add as library..."

EDIT: You can do "File" -> "Invalidate Caches...", and select "Invalidate and Restart" option to fix this.

EDIT 2: This fix should work for all similar incidents and is not a twitter4j specific resolution.