I just fixed this at work because somehow a co-worker changed a folder to Read-Only (apparently by accident) and no one could modify anything…not even the architect of this fiasco. The issue is when you uncheck the Read-Only attribute, click Apply, and OK. The Read-Only attrib doesn’t stay unchecked. So you need to use the Attrib command using the command prompt:
use attrib -r +s path_of_folder (example: attrib -r +s c:\test)
you might need to use attrib -r -s c:\test if a program is not working correctly that needs access to that folder.