This is not a MATLAB problem, because MATLAB is just passing on information to you about what your computer is allowing it to do.
A week ago, your computer may have been different.
READ THE ERROR MESSAGE. The directory no longer allows write access to that directory. The change may have happened because of a corruption problem on your drive. This is often minor, and can often be repaired. Check the write privilege on that directory.
It is your computer (I assume.) You can reset the write privileges on a directory, IF you have admin rights on it. I'd first check to see that your drive is not corrupted, as that will only get worse with time.
