I've been playing on this server for a couple of days now and it seems pretty nice. Low population, but cool people so far.
Unfortunately, I can no longer connect. I'm getting a client crash with a fun "Failed to register dimension for id 2, provider type 24 does not exist"
Nothing on my client changed, and I can play single player and multiplayer on my own server just fine. I re-downloaded the modpack just to make sure it wasn't on my end. Did you add or change any mods by chance?
I logged out in the main world near my base if it matters. My IGN is DTwenty, in case there is something wrong with my save file and you need to modify/remove it.
Thank you for looking into it. I look forward to coming back to continue building and getting my shop going.