SomaSoul

UPDATE: We tried more tests on fresh installs, and even with a vanilla world with Forge, the issue arises after a players inventory changes/they gain new items or blocks and then try to rejoin. We also tried fresh installs and fresh worlds with a variety of mod combinations, and we are almost entirely certain this is a Forge problem with referencing player data. I hope this can be fixed soon; I don't envy the Forge devs right now, coding is hard. Best of luck to you!

Minecraft 1.18.1 Forge 39.0.9 and 39.0.10 Connection Lost Internal Exception: io.netty.handler.codec.EncoderException: io.netty.util.IllegalReferenceCountException: refCnt: 0 My brother, my friend and I have tried all sorts of combinations of our modpack to try and play modded 1.18 together, and its only about 50 mods or less, not counting dependencies. No matter what mods we include/exclude, the above error shows up for anyone trying to join my Survival LAN world and they cannot join. It says they joined and left in the chat almost instantly. We tried with and without the bigger mods we're wanting to use such as Terralith 2.0 and Create, but even a fresh world without these mods still causes the error. We also tried the latest Forge version. We're at a loss here, I have no idea what's causing this and it's very disheartening. Any help would be greatly appreciated, thank you for your time.

Hey my brother and I are running into this same issue (Connection Lost Internal Exception: io.netty.handler.codec.EncoderException: io.netty.util.IllegalReferenceCountException: refCnt: 0) and I had originally tried to run the server with Create, but before he joined (I'm hosting on LAN), we removed Create and Flywheel from our mod folders and were able to play for a few hours before this error started persisting for him every join attempt. We definitely don't have Create included, did it perchance cause some sort of residual changes to other files?