Class and file not found for Unity project

Hi! 

I found a file not found issue in the Rider.

Problem

Rider said files/ classes are missing even those file are located in the correct directory! I have tried to build and clean the project, even I have restarted my macbook pro, none of these solution work.

How can I include all the existing C# file into the project?

At the same time, Rider got some none existing files in the solution explorer (the file have been deleted long time ago), how can I clear those non-existing files?

Any advice are welcome! Thanks!!

More about my environment:

• Macbook pro (Late 2013)
• Jetbrains Rider (2017.3)
• Unity (2017.02)