Unity opening fails

When I try to open unity, it says FATAL ERROR Detected multiple Library folders within your project.

Did you copy a project into this project? Use "Export Package" to move assets between projects.

You need to remove the following Library folder(s) from your project before you can open it again:

/Users/Shared/Unity/AngryBots/My project/Library

I've tried everything but i don't know what that means someone please help me.

Thank you