Hi, I've been playing on a custom modpack for nearly 200 hours now and ran into an error.
Note: This isn't the exact screenshot from my game but this is the exact error message.
I was attempting to add in a block called magical soil (a part of the allthemods modpack) which said it originated from the kubejs mod. I copy pasted in some files but it never showed up so I replaced the whole kubeJS folder with one from the ATM9 modpack but this created a bunch of errors because of missing mods so I tried restoring the old folder. The game doesn't crash anymore but it gives me this "Errors in currently selected datapacks" message.
I tried renaming the level.dat_old file to level.dat as some people recommended but this didn't help at all. I noticed some mods were missing but even after adding back in the ones I saw the error persisted.
Edit: Pastebin Files
The log files is quite large and I have no idea how to read it, had to cut it into 2 parts:
Crash Log 1
Crash Log 2
When trying to create a new world the game crashes before getting to the screen and gives the exit code -1 and this is the crash log
World Creation Crash
I had the same issue when I was making the pack and I eventually solved it by removing the mods that were conflicting/crashing but I suspect that this wouldn't solve the issue with the already created world. I was thinking that maybe the issue was a mod that accidentally got disabled/removed but I'm not sure.