Having a bit of trouble figuring this one out. Everything seems to point to ccl but I am wary to point fingers at it in this case. Maybe I am missing something that is causing it to throw an error? Anyways, here are some of the relevant pastes:
https://paste.dimdev.org/lacumarugi.mccrash
https://paste.dimdev.org/ziwososuka.mccrash
https://paste.dimdev.org/zokohugido.mccrash
https://paste.dimdev.org/igutixorus.mccrash

In the interest of thinking that it might not be ccl causing it here is a list of current mods in the pack:
mods

Let me know if there is any more info I can get you (logs from server members?) or if I should bark up a different tree.

edit: After testing quiet a bit in single-player it seems it has something to do in connection with the server environment. Not sure if that helps at all but it cut the ccl "tagged" crashes from 4-6 per hour to not one. Is there something different in the way things are handled between a local world and a server?

Not sure what caused this but something I updated seems to have removed the issue. Closing for now.