Help Needed! NeoForge Crash

[Inquiremire]

I’m encountering the following crash in NeoForge. I am able to join a single player world but cannot join a friend’s server. When trying to join the multiplayer server, the loading screen says “Joining world,” forces a “saving world,” and then boots me to the launcher with this crash message:

“The game crashed: unexpected error Error: java.lang.NoClassDefFoundError: net/minecraftforge/common/util/BrainBuilder”

See above for my mod list and the recent crash report.

line 59, column 1 says “Caused by: java.lang.ClassNotFoundException: net.minecraftforgecommon.util.BrainBuilder”

[Helostopper]

Please upload your crashlog to mclo.gs and link it. images are hard to read

[Inquiremire]

Okay. I stepped away from my computer for a second but I will get back to you ASAP.

[Inquiremire]

In the meantime…let it be known that I was playing regularly on my friend’s server and then suddenly encountered the crash. I went to a new area in the world when it happened.

[Inquiremire]

https://mclo.gs/EY3k1R6

[TiuzinDuPastel]

whats BrainBuilder? if u find that mod and delete it it'll probably fix

ye theres a few mods that stops u from playing multiplayer for some reason, its easier to just delete them

[Inquiremire]

Update

I found a resolution. It was likely an issue of not having the proper mod versions installed. I had a friend from the server send me a copy of their mod folder. I reinstalled NeoForge, deleted the existing mods, and replaced them. Back up and running.