Is there an existing issue for this?

• I did not find any existing issues.

Current Behavior

Writing a report after seeing someone in FTB Evolution discord have this issue, where their game crashes upon loading their save (single player). They noticed this when loading their world in Evolution 1.24.2 after updating from 1.24.1, however, that small hotfix only updated Oritech and left EnderIO untouched. Upon further investigation they realised they could replicate this issue in a fresh 1.24.1 instance too, so effectively after their last session this world started to refuse to load and they rolled back to an older backup to continue playing. Unfortunately I don't have further context on what they did, what they placed down for this to happen (nor did they seem to specifically know).

I've received the world save from them and trimmed it down to just the problematic area (their overworld home, where level.dat's player also spawns you in), the entire world looks like this:

After selectively deleting chunks to find where the problem lies, I've found that the very bottom left one, which is chunk 53, -1 in region 1, -1, when deleted allows the world to load, so when the world looks like this it loads fine:

I've also confirmed that loading the world as is/unchanged but with EnderIO mod disabled in the pack, the world also loads (the crash stacktrace pointed at something in enderio but wanted to confirm it's related).

The world upload in question (~3.5MB): FTB Evo.zip

Expected Behavior

Save to load without crashing

How to Test

1. Load in the world in an FTB Evolution 1.24.1 (or 1.24.2, same EnderIO mod version) instance

Local Environment

- **Operating System**: Windows 10 and Windows 11
- **Java version**: 21.0.4
- **Minecraft Version**: 1.21.1
- **Version**: enderio-8.0.5-alpha
- **Other Mods**: FTB Evolution 1.24.1 / 1.24.2 modpack

Any Additional Information?

My Crash Assistant output from the reproduction:

FTB Evolution crashed. The logs have been uploaded to gnomebot.dev:

latest.log head / tail (~15MB & ~136k lines) | debug.log head / tail (~61MB & ~410k lines) | crash-2025-10-28_00.30.00-server.txt | KubeJS: client.log / server.log / startup.log | crash_assistant_app.log | modlist.txt

Mod list changes on top of the modpack:

�[2;32m3�[0m added, �[2;31m2�[0m removed, �[2;34m97�[0m updated.

Krylle028's Crash Assistant output (original person having this issue, it's their save):

FTB Evolution crashed. The logs have been uploaded to gnomebot.dev:

latest.log head / tail (~37k lines) | debug.log head / tail (~18MB & ~115k lines) | crash-2025-10-28_05.37.30-server.txt | crash-2025-10-28_05.37.45-client.txt | KubeJS: client.log / server.log / startup.log | crash_assistant_app.log | modlist.txt | win_event1761601079168.txt

Mod list changes on top of the modpack:

�[2;32m3�[0m added, �[2;31m2�[0m removed, �[2;34m97�[0m updated.

Thanks a lot for the thorough workup and world download - I will investigate and report back :)

O a bit of new info, the person went back to 1.23.0 of the pack to play there with the save and it works fine, so I went to check it out and EnderIO mod updated in between.

So I went to try this out in 1.24.2 of Evo, and it crashes by default, but if I load it up after manually downgrading EnderIO from 8.0.5 to 8.0.3 (what 1.23.x of pack used), the world loads fine. So it can be narrowed down to something that changed between 8.0.3 and 8.0.5

Edit: also loads fine on 8.0.4 so it's something between 8.0.4 and 8.0.5

Thanks for the world, I was able to find a way to correct the problem - I might spend some more time investigating why this fix was required, but I'll get a hotfix release out shortly for this issue.

Thanks again for the A+ bug report, it was incredibly helpful :)