Ideas
Update to clarify. When I noticed my pics on the wall were black, I quit the game without saving. Then, I looked in my Screenshots folder and my photos were all there.
Before the Jan update I did not backup my game. I usually backup before update but didn't this time.
On PC or Mac go to your files - Electronic Arts/TheSims4/Screenshots.
Look at your photos in the Screenshots folder. Select file view to Preview/thumbnail. If they are normal, then you can copy/paste the pics to a new folder on desktop (outside of the EA folder) to save them until EA fixes the bug or you learn how to make your own CC photos in Sims 4 Studio.
That's what I'm doing later. Making CC with my screenshots. 🌟
Whenever EA releases an update, a backup is mandatory. It's unbelievable. Always save the following folders: Mods, Saves, Tray, and screenshots.