Why does several of my scripts that used to work now have error messages such as "The namespace '' already contains a definition for (examplescript)"

Everything was working as intended when I left off, but when i reopened my unity project, i was faced with several errors in my scripts. When i view objects with scripts in the inspector, the scripts say "The associated script can not be loaded. Please fix all compile errors and assign a valid script." Does anyone have any idea why and how to fix this mess? I really need help because I'm clueless.