Friend and I are having issues using a headless server. Sometimes one can join but not the other, or both of us can't join. Disabling this mod has fixed it. This is not common and generally requires a restart of the server to fix it for a while.
I got another bug report on the forum. I know I'm 2 months too late, but if you could possibly reproduce this bug and send me the desync report on the forums, I should be able to do something about this. Thank you!
