Hello everyone! I recently had the unfortunate event happen after aging up a sim using the Age of Instant spell (TLDR: he became old and ugly, pics attached). I've been looking at the resources found here in this subreddit and downloaded IFF Pencil 2, hoping to be able to follow [these instructions](https://www.reddit.com/r/thesims1/comments/1l9em1l/comment/mxc7mof/?share_id=5zPVrgGuzQ4VVEXz96-bl&utm_content=2&utm_medium=android_app&utm_name=androidcss&utm_source=share&utm_term=1) (but obviously applied to the head, thanks for the highlight u/wixbloom), but am having some difficulty.

  
Error 1: After downloading and extracting IFF Pencil 2, trying to run the app comes up with an error that says "Can't load The Sims\\GameData\\Behavior.iff!" Would this affect anything? After I press OK, the app opens fine anyway.

I got as far as navigating to the The Sims\\UserData\\Characters folder, but it seems as though the characters I created are just not in there!  
I will mention that I am using the Steam Legacy version of the game. I originally installed and have been playing the game since Feb 21, but on March 3rd, Steam asked me to re-install again. I thought it was weird that the game had suddenly disappeared, and I was worried it would overwrite the family I'm currently playing, but after installing again, my custom family was still there, so I just clicked on their household and continued to play.   
  
I did some digging and it would seem as though I have two copies of the game downloaded. I did boot up both sims.exe apps to see if there was a difference, but nothing that I could see.   
I also browsed both folders UserData\\Characters file folders, and both only show User00000-User00023. (Screenshots attached with the file folder navigation pathways included, along with their "date modified".)  
Opened the STEAM app and went STEAM > Sims > Properties >Installed Files > Browse, and it verifies that I should be looking at the more recently installed files (from March 3rd).

On March 3rd after my re-install, I did create a new family (the Supreme Family) that had my desired head and body in anticipation of the transport, but it would seem like they aren't in the UserData\\Characters file either. I took a look at the Create a Family tab in-game, and it would seem as though there are no custom families at this time, which would explain why there is no new character data in the userdata files.

Not sure if there's a quick fix in my case, or if I should just kill the sim in question off for causing so much grief! Would uninstalling/deleting game files and re-installing the game solve the issue? Would that be the end of the Framboise and Supreme family?

Any insight would be greatly appreciated!

Changing a sim's appearance with IFF Pencil 2 - Technical Help - User Data Glitch/Bug?