Patching a copied module?

Hello, I'm currently running a Curse of Strahd campaign but it was copied from a base version.  I have since added a lot of custom content to the copied version of the game but discovered something very discouraging--all the monster/NPC character sheets seem to be broken.  None of the modifiers for attributes calculate, even if they display on the sheet--when I go to edit a sheet they are all set to 10 with +0 modifiers.  None of the sheets are updated for spells and the like either.  I read elsewhere that someone had a workaround for patching copied games but I can't seem to locate where that is explained.  I don't want to go through and custom edit hundreds of create character sheets if I can help it and starting a new campaign and porting over all my custom content would probably be a lot of work too.   Anyone know what the issue could be or how I can fix it?  Am I able to patch copied games?

I'm following this. I made a copy of a homebrew adventure I've spent a ton of time on and after reading this I checked it out. All the PCs and NPCs I created don't even have character sheets in the new game. 

Come to think of it, I'm not entirely sure it's a copied game.  It was set up years ago and then I came back to it a month or so ago.  But either way, none of the stuff in it appears to be updated and all the character sheets are pretty useless as is.  >.<

So I did a little digging and the problem for me was that I had not yet specified a character sheet for the copied game. I assumed when you copy a game you copy the settings as well but you don't.  Once I went into settings and chose the same sheet as the original game, everything was good to go. 

Glad it worked out, but just so you know: you can patch copied games. In fact, if you are ever concerned about a patch overwriting or affecting your custom content, you can copy your current game, apply the patch to it, and then review content within it to see how it will affect your real game. You can then decide if the patch is OK.

The character sheet not being selected isn't my issue.  My issue seems to stem from this prompt whenever I open an NPC for the first time.  You can see under the prompt that modifiers under the attributes aren't calculated.  Spells also won't be loaded into the sheet either.  Not sure what the cause is.