Description of the issue:

• Spawned into the world with an immersive engineering workbench, the workbench had a blueprint in it.
• It will also crash if the blueprint is placed into the workbench.

This was running on a personal server, the client crashes but the server does not.

Crashlog:

https://pastebin.com/QKS3SXK4

Versions & Modlist

Forge: 1.16.1 forge-32.0.108
IE: 1.16.1-3.2.0-115

Modlist: https://pastebin.com/k5vNFa3i

seems similar to bug fixed in 736084b, crash seems to be different however

Is this issue reproducable? Does it keep happening?

it keeps happening on join, it affected my friend at first, it started after adding a new mod to the modpack, removing it seemed to fix it. after crashing due to another bug we had to do another mod change and then it started affecting me, i will try removing the mod i just added and see if it crashes again but if it stops crashing because of this I'm not sure what's causing it because two different mods seemed to "trigger" it.

Tested joining the server a couple of times. Crashed 3 out of 5 times, the only times I didn't crash was when I loaded single player first.

so repro steps:

• Have IE workbench with blueprint placed in the world.
• Join server

Temp fix:

• Load singleplayer world
• Leave and then join the multiplayer world

Looks like something doesn't load properly and is then loaded when singleplayer is loaded first.

I guess here is that due to everything being multithreaded now, the render thread tries to access the recipe before recipe loading is complete.

@malte0811 maybe we should initialize all our recipe lists as empty and then replace them during loading? That could help prevent these multiple NPEs we've seen so far.

This should be fixed in recent versions.