That's not the debug.log
Your error is a network protocol error. It typically does not tell you which mod caused the problem.
Those errors are usually caused by
* Mods that were never tested by the mod author in multiplayer
* Mods for different versions of minecraft
Usually the only way to find the problem mod is to experiment with removing mods until the problem goes away.
Backup your world before removing mods.
Getting this error is also an indication that you are developing your modpack in the wrong way.
* Do not just dump a large number of mods in your mods folder and expect it to work, it won't
* Add mods in small groups and test it. That way you will know which mods are causing problems, it one of those you just added.