Sims won't open after I got the Realm of Magic Pack

I had the same issue, and I did a bit of research only to find out a lot of responses are only saying to take out your mods, repair the game and put the mods back in to figure out whichever mod is causing the issue, and let's face it that's annoying to do bc anyone who has mods for the sims ends up downloading a lot. I was experiencing a different glitch where my Sim would just stand there which was an issue with the game itself not any mods, and it dawned on me the fix might work for this too, it's a cheat to reset a sim. When I ended up trying it it solved my issue, the vendor walked back to the shop and opened up within a few seconds.

You would do the following:

Ctrl + shift + c 

The cheats bar should pop up in the top left of your screen, type into the bar this and hit enter:

testingcheats true

Then type in this followed by the whatever the vendor sims full name is and press enter:

resetsim 

And to turn off the cheats again you type in:

testingcheats false

Then press enter and escape to close the bar