Okay so, I turned Destroy back on in the server and game, and now it works again for some reason?
Whatever the case, it seems solved now so, thank you.
We both joined successfully, although I do want to clarify that it worked before when we both had Destroy installed.
I still would like to play with it installed, I'm just unsure of why now it's an issue that's causing my friend's game to crash, despite it working before.
LOG: https://mclo.gs/8iKyww8
Me and my friend are doing a Create play-through, and he cannot join my server, even though I joined with the same mods as him with no problems.
I appreciate any help.