What I mean is that the problem is not completely new and existed already years ago. It then got fixed and now seems to appear again with the newest version.
I'm afraid the developer - in his aim to let the registry cleaner find as many "erroneous" keys as possible - has forgotten to exclude those UserAssist items from the scan.
Deleting some type of those entries unfortunately causes the user to loose the list of recent programs from the Start menu.
So as long as this issue is not fixed in the program, fro reasons of safety it's highly recommended to exclude all Userassist items from the registry scan through adding the text "UserAssist" (without quotes) to the "Ignore words" option of the Registry Cleaner and to add "UserAssist" to the Global Ignore List in the Program Settings (go to Settings > Advanced > Global Ignore List).