When you enter a portal to the Runic Dungeons world, you get teleported into a wall and suffocate. The blocks around there are admin protected as well, so we can't break them. If you want to give it a try, my portal is at x:2228 z: 2008 y: 69
I tested the mod in singleplayer, it seems like the world we get teleported to on the server is a very different one. Maybe there is a dimension ID conflict?