Managed to make it to Omothol, and after encountering issue #248 I tried to right-click on a Remnant. It opened up a trade screen and a few seconds later it crashed. I'm assuming this will be fixed in a later update with the other issue?

Can you post the crash report? I haven't encountered any crashes in regards to Remnant trades recently.

Unfortunately, I'm not the one with access to the server's files. I'll see if I can find them.

The server admin gave me this gist.

That seems to be caused by Soot. Considering that version (0.1) isn't available on the mod's CurseForge page anymore, maybe try updating the mod and see if that solves it?