Android Studio and android.support.v4.app.Fragment: cannot resolve symbol

Question

I am tryng out Android Studio instead of Eclipse. I install it and then start a completely new project and follow the wizard. I add no code of my own.

Then, I right-

Answer 1

I encountered this issue and tried everything including File > Invalidate Caches but nothing worked. The reason this issue was happening for me was because I had external projects that were using a different AppCompat version to my main gradle file.

After I updated all gradle files to be the same version the compile error went away.