Server kick on PneumaticCraft item charge change

[kd8lvt]

Modpack version
Enigmatica 6 v0.2.17

Issue
Hosting a server for a few friends, and starting today we've been getting kicked from the server when any of us go near each-other. Originally, we thought it was PneumaticCraft, but we removed all our PC items, and it's still occurring. The only error message we get is:
Internal Exception: io.netty.handler.codec.EncoderException: java.lang.IllegalStateException: LazyOptional is empty or otherwise returned null from getValue() unexpectedly
We're not sure what the problem is, but the trigger to start it seems to have been PC, and now it's just happening whenever players congregate. Note it still (seems to) happen whenever the pressure level changes in a PC item or armor, kicking all players within render distance, apart from the one who did it.

Logs
Server latest.log: https://pastebin.com/RDTdASXc (A join/kick happens at line 15. The panel I use truncates the latest.log, annoyingly...)
Client latest.log: https://gist.github.com/kd8lvt/0b57c26bf4d4ba79826b9d2e457d1786 (The final log spam about the sound engine is unrelated, I think.)

[NielsPilgaard]

Thanks for the report, can you reproduce this without Optifine? :)

[kd8lvt]

Thanks for the swift response!
It's kicked everyone who's played, so it's likely not Optifine, but I know that OF is dumb - here's a client log, from a player who doesn't have Optifine installed. https://gist.github.com/kd8lvt/724142ba1b2430e613de2efee3533c19

Gist

latest.log - no OF

latest.log - no OF. GitHub Gist: instantly share code, notes, and snippets.

[NielsPilgaard]

Hmm, I see a number of issues at the end of that log, most of which I think will be fixed in the 1.16.3 update :)

[kd8lvt]

Good to know! Any idea on an ETA or just 'when it's done'?

[NielsPilgaard]

ETA this saturday evening, so ~3 days :) it may change though, if we run into issues or mod releases are postponed.

[kd8lvt]

Thanks :) We're all having fun, apart from the occasional hiccups - good to hear we're updating soon :D

[NielsPilgaard]

I'm glad :D
Just so you know, while we recommend you start a new world in the coming update to 1.16.3, it's not required, but we cannot guarantee you won't run into weird issues :/