Help RE: Cannot find builtin function 'whos'

Last night MATLAB 2017b worked fine, but when I opened it this morning, there was a popup message which said

This was accompanied by the following in the Command Window:

Following the instructions in the warning just repeated the initial popup message and declared "Undefined function or variable 'computer'.

Any ideas what I have done, or how to fix it? I have never even heard of builtin before.

Answer 1

[Jan]

Something has destroyed your Matlab folder. Either important function have been deleted or destroyed.

The solution is simple: Restore the Matlab folder from your backup. Under Windows the "Recent Versions" might be useful. If you do not have a backup - bad idea. You have to re-install Matlab.

Actually modifying the Matlab program folder should work with admin privileges only, therefore it is recommended not to work with such high permissions.

[Dominic Saunderson]

No backup I'm afraid, so I guess I'll have to re-install it!

Thanks Jan, your answers are always very clear and patiently explained for beginners.

[Jan]

You are welcome. This is the right time to create a backup for all your data.