Error unlocking system - "Must provide a Master Application path."

I have two identical computers set up with Inteset version 2.00.102.  The system was set up in 2014 and is running in a clients museum.
I had to do maintenance on the system and in one and only one of the computers, I could not exit Secure Lockdown.  Alt-Shift-S brought up the dialog box, but when I told it to disable lockdown and "Apply", I got a message saying "Must provide a Master Application path."

I could not find a way to get out of it and ended up using an alternative admin account.

From the alternative admin account I could see that the path and files for the program were where they were supposed to be.  

Any suggestions for fixing this problem?

Keep in mind, I can't really upgrade to a newer version until I unlock the old one.

It's unclear what would cause that message. You may need to delete the locked down account and rebuild it. Also, it is suggested that you register the systems withe the Inteset Remote Management service (free). That way you can perform software upgrades remotely and much more

There is no external internet at that computer so remote management is not helpful.