Android Studio “cannot resolve symbol” but project compiles and works

Question

The project compiles fine. However, Android studio 3.0.1 shows reference to one particular library in red and displays \"cannot resolve symbol\". Even single stepping into

Answer 1

Following has resolved this for me.

1. remove library from gradle cache (in case of linux, it's in ~/.gradle/caches).
2. remove library dependency from the build.gradle and sync
3. restart (maybe invalidate cache)
4. add library dependency to build.gradle and sync
5. clean and rebuild