MadGrin

Ah, thanks for the pointer to this.

When I load the same version of Forge outside of MultiMC I don't see those client logs. Pretty sure it's some magic that MultiMC is doing. I'll take it up with them.

Lex, I pushed my modpack out to https://github.com/cdempsey/mac-pack-2. During testing I just let the /config files generate and didn't change anything in them on the off chance it was some config option I'd set. I've also noticed that same client log message in every MultiMC (both 1.7.2 and 1.7.10-based) instance I've got that as Forge loaded. Methinks it's something going on there with MultiMC but I'll take a look.

I'll see about getting my mods into a GitHub repo (I need to do that anyway) for you to pull from. I've got no idea about the message you put up but I'll poke around. Maybe it's something crazy MultiMC is doing but it's odd since: [10:53:04] [main/INFO] [FML/]: Java is Java HotSpot 64-Bit Server VM, version 1.7.0_51, running on Mac OS X:x86_64:10.9.4, installed at /Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/jre

So while trying to help troubleshoot this a bit I tried a "binary search" against my set of mods. I took the top half of them and put them in a client and separate server. This worked. Then I took the bottom half of my set of mods and put them in client and separate server and it worked as expected. So then I started combining the top and bottom sets until it broke. Like the OP mentioned it doesn't appear to be a specific mod as all of them at one point were in a test set that worked without the error. Sometimes I was able to get 42 mods to load without an issue and others it would have the error with only 39 mods installed. I don't think it's the number of mods but possibly the total number of things (items, entities, blocks, etc. etc.) that the mods add/register with Forge. Maybe it has something to do with the client telling the server what mod things it knows about that it doesn't have to tell it in single player mode? But that's just my guess. Hope this helps.

I'm having the same issue too. I'm running Forge Mod Loader version 7.10.18.1180 for Minecraft 1.7.10 with roughly 40 mods. Everything works like a champ in single player mode but as soon as I try to start up a server I cannot connect with the exact same error: "NetworkDispatcher exception io.netty.handler.codec.DecoderException: java.io.IOException: Packet was larger than I expected, found 65536 bytes extra whilst reading packet 63" Posting my fml-client-latest.log in case it helps:https://paste.ee/p/zXHI9 edit: Fixed link to actually link