Every time I try to open the catalog since the 2.1.1 update, my Playdate crashes with the falling blocks. "More info" says "pdxinfo file not found." I saw someone else report the same thing here.
The last entry in errorlog.txt:
2023/12/08 08:55:02
/System/Catalog.pdx
pdxinfo file not found.
Anything I can do with forced firmware from the SDK or something? Or is my only hope a factory reset? I have so many sideloaded games!
did you try removing catalog app from settings -> games and then reinstalling it ?
Oh geez, I didn't realize that was a thing! I went to Settings and scrolled to the bottom, it showed Catalog as "Uninstalled"! Installed it and I'm good to go!
Not sure what happened, I definitely didn't uninstall after the 2.1.1 system update... 
That's odd indeed. And it shouldn't have showed up in the first place if it was missing.
I would also add, mount the Playdate Data Disk (Settings -> System -> Reboot to Data Disk) and run Disk First Aid on it (or whatever your OS has). That will also resolve any disk issues the Playdate may be having.