The associated script cannot be loaded- How to fix?

“The associated script cannot be loaded. Please fix any compile errors and assign a valid script” i have a very simple script with no compiling errors, i keep making new scripts and none of them work, all having this same error.

Not enough info really.
Is the script attached to an object in the scene?
If you create a blank class script does it work?
Are you using c# or javascript?

If you post up a script example we might be able to help.