Hi there,
i have a CTD concerning Mekanism (in use with other mods). I am Using the YogsComplete-Pack and i can recreate the CTD.

I have disabled these mods: MekanismTools, QuarryPlus, Soul Shards Reborn and Remain in Motion.
Basically i have enabled everything except ExAliquio/Nihilo and EIraIRC. As a Map i selected Opis.
Enabling or disabling any of these does not change anything.

When creating the World on the Server i use the Seed: Land_of_Confusion
Level Type is BiomesOPlenty.

I've tried reinstalling on CLIENT and on SERVER.
The issue only occurs when i playing MP. Map resets dont change anything. It always crashe around the same spot. Once i have the CTD i can't access the Server anymore due to CTDs when loading. As long as i avoid the said Spot i can explore the Map.

Also i have disabled Balloons in the Mekanism Config by setting their ID to zero. I still get the CTD. I really don't know why.

The Crash Reports can be found here:
(I have multiple of both, These are the newest ones)
http://openeye.openmods.info/crashes/8bf7ef2fd1010580928d03618f8a3578
http://paste.atlauncher.com/view/daf2aa85

The Logs from the Server state this during the Time i was on:

[INFO] Someone [Ip] logged in with entity id 7243 at (-163.5, 69.0, 254.5)
[INFO] Someone joined the game
[INFO] Someone lost connection: disconnect.genericReason
[INFO] Someone left the game

The Server does not crash. It's just the Client.

If you need anymore information concerning this you are free to ask me. I could also give you the ip to the Server i am using so you could try it yourself.

Looking at the code, the change I've made means that Balloons won't even be present in EntityList.IDtoClassMapping, which is where the NetClientHandler was somehow getting it from, any more. I'm assuming that S0FPacketSpawnMob/Packet24SpawnMob are only supposed to be used for vanilla entities.

I think it's fair to say that we have done everything in our power to try and fix this - going to close.

I am not aware of the complete status, but thought I should leave this bit of information here:

Players on our Yogscast complete Pack 2.4.2.9 (with Cauldron as server) seem to get this crash when the ICBM mod is installed client side, but not server side, then when they remove the ICBM client side the issue is resolved.