@hannahlong090
Having the Moschino stuff pack and the patch preceding it are all you need to be able to add frames to photos.
Actually the patch is what added this new base game option to frames.
Just now I tested with a non-skilled (no photography skill) Sim. Small pictures were taken with both the phone and a regular camera.
The photos were placed on a wall and I was able to add frames to all the photos.
Are you on PC/Mac and do you have any Mods/CC?
Try removing (not disabling) mods / cc and delete the localthumbcache.package and any other cache files.
Test the game to see if the issues are still there.
Testing an a new freshly generated folder is the best way to investigate and resolve issues.
Instructions and other information is in the link below:
Troubleshooting tips
https://answers.ea.com/t5/Technical-Issues-PC/READ-FIRST-Troubleshooting-your-Game/m-p/3621199
- EQ Avid Sims Player
Game Version 1.54.120.1020 Patch 08Aug2019
All content installed thru Moschino Stuff Pack
PC / Win 7
Never used CC or mods.