A possible reason can be that those files have fallen out of MATLAB search path or some issue with 'pathdef.m' file. Here are some troubleshooting steps which you can try:
- Save a copy of current MATLAB search path:
Above command gives the current location of 'pathdef.m', ensure that you make a copy of the file by copying it to a different location than its current folder.
- Restore MATLAB Search Path and rehash toolbox cache:
- After above step, check if the issue of missing files is resolve and then you can save the new MATLAB search path to 'pathdef.m' file by following command:
Hope it helps!