When I tried to open Malwarebytes, from the Start menu and then Programs, I get a message saying mbam.exe is no loner valid.

When I tried to open it from Computer, then Program files, it did nothing.

When I tried to download Malwarebytes from the site, a window pops up saying:
Internal error: Failed to expand shell folder constant "userappdata"
then
Setup was not completed
Please correct the problem and run Setup again