@DaniRose2143 Most likely the exception is being caused by another mod, MCCC is just making it so you can see it happen. You could try adding mods back just a few at a time until you find the culprit. I keep mods in folders named for each mod author and when I'm trouble shooting I move one folder back at a time, to identify which "modder" has a mod with an issue. It's the same principle as the 50/50 method, but different.
Anyway, the reason you are having problems with discord is because you are following the link at Deaderpool's website and it is outdated. The MCCC support channel is different now. Go to
his patreon instead, the link for discord support there, which is in the very top post under "About Deaderpool," is current.
There's a "Start here" channel, so if you follow the right link to open discord you will definitely know where to go next.