I also have had the same issue when trying to change companies.  I have tried re-building files and everything that has been suggested.  Still nothing.  When I go to use 'help' in the icon bar - it does nothing and freezes!

I have been using QB since 2004 and have never had this many issues.  Something is going on with programming and it needs to be fixed.  Not getting resolution is NOT ACCEPTABLE!  When a small business relies on this program to work and it doesn't, it can be crippling.  What happens if QB quits working at all?  There is no customers should have to upgrade to 2023 to get the software to work. (It isn't free!).  Please come up with a solution - year end will be here before we know it and this cannot continue!