I can confirm this is happening. I opened Minecraft after 1.21.120 installed automatically. I used to have a bunch of stuff (add-ons, custom skin packs) in the com.mojang folder that’s suggested by the Creator Guide (link). But now it appears like I have no add-ons or skins, which will potentially break my modded worlds if I open them. Seems like the code isn’t loading the original “com.mojang” folder anymore.
Hope this can get fixed soon, I had to cancel a gaming season with a couple of friends because we’re afraid we delete our addon-related progress.
Yes, that works! Thank you, I didn't know that was possible (though it was a bit confusing tbh), so sorry for the additional noise 🙂
Edit: Though I first tested this issue on a creative, addon-packed world, now I tested on a Survival, normal mode and the same issue happens (as you can see on my latest screenshot).
The issue was fixed to me, thanks! I still lost part of my work, however some entities from an add-on re-appeared on chunks that I didn't visit when the error popped in. Thanks for fixing this!
I can confirm this is happening on Windows. I am using Bedrock version 1.20.71, and add-ons from my worlds stopped working. And while they appear activated to me in the world info, and present no errors/warnings, when I load the world the addon contents don't exist.
Tried out the video, but just then Minecraft deleted all my own resource packs and behavior packs (after “updating” them when I opened back the game) without a way to recover them. I believe I only had to move the desired packs instead of the whole com.mojang structure, but I messed it up and lost all my stuff, things I didn’t save anywhere else (my bad of course, I should have expected Minecraft to suddenly delete my files) and will break some worlds. Honestly I feel bad about this, but I guess it’s all my fault because it was an expected behavior, not a bug.
Thanks for the explanation!