Clayto: Yes, I am afraid you are right. It is suspected that there is a bug in the November update for which the PowerShell command to re-register apps is a trigger. I just hope that Microsoft is about to issue a fix.
The November update bug
I had been hoping Microsoft would have issued a fix for the November bug by now, but as January comes towards an end without anything from them it looks unlikely. I am not often prone to criticising them, but this has been a bad business. I fear I am going to have to get my head round a re-install, as some users have recommended. I follow quite a few different forums in which I have not encountered a single example of someone resolving the issue other than by re-installing.
I think it may be worth explaining how I came to be caught by the PowerShell app re-registration trap, as someone who had never used PowerShell before. It was as a result of using the FixWin 10 Tool produced by The Windows Club. One of its features is the procedure to re-register app(s) with a PowerShell command, which I hoped would repair a corrupt Calendar app. The rest as they say is history. My Calendar app is still in need of repair, to which is added the Store, plus a large number of important Microsoft apps which are in an even worse unusable state, and several third-party apps as well.