Using Terminal (In Applications, Utilities) change directory by typing cd .assistant Then type ls -l to view all the files. You will notice that each file here has an extension of .QCad. Remove all of them by typing, rm *.QCad.
Once you restart QCad, your help files will now be working correctly. Search will work and also the left sidebar content.
Finder will not let you see the hidden folders which is any folder that begins with a dot, such as the folder called .assistant.
Took me quite a while to figure this out as a previous poster here had said they tried that and it didn't work. Well perhaps they didn't do this for EVERY user profile on the system.
Too bad RibbonSoft doesn't make this fix more obvious to their paying customers such as myself. If it wasn't for the fact that QCad was such a great 2D CAD program, I would have refused to invest so much time for free...LOL.