Version Information

Forge version: 1.16.4-35.0.17
Botania version: 1.16.3-409

Further Information

http://pastebin.fr/73243 (sorry if the link isn't formatted correctly, it's the first time I do this).

1. Get hit by a skeleton arrow (or take any damage by a mob)
2. Game crashes (tested it on server and in single player)

What I expected to happen:
Lose HP after taking damage.

What happened instead:
Game crashed.

As noted above, the solution is to update Immersive Portals to 0.10 or above

This is happening on Fabric as well :concern:

#3382

Can you try with just botania then add mods until it doesn't work.

Same issue as this (and #3518 I suspect), it is caused by Xaero's World Map, somehow, as well as Immersive Portals. That was extremely annoying to narrow down, which is why I suspect that the others who got this bug just sat around and waited for someone else to find the fix first (thanks, guys).

Something else that might be relevant is that it's a bit inconsistent. At least one configuration of my mods would crash if I took damage, and work fine if I removed Xaero's worldmap, something I tried at least a few times just to make sure. However, I can't recreate that with only xaero's worldmap and botania. Immersive portals is a mod shared by both me and the other ones reporting the crash, so I'd focus on that one more.

I can confirm that after adding Immersive Portals to our pack, we started getting this exact crash.

Turns out this is actually a problem with the Immersive Portals mod, not Botania. I've made a PR to the original mod that fixes the issue. If you just want a working build, I've also uploaded the fixed jar as a release here.