[1.7.2]Bug report, Portal in Tannen's Tower disappear

[zizi12321]

I'm a stone arcane blade. This is the first time I go that far in nightmare adventure so I'm very disappointed.
When I kill the dragon golem the portal just appear on one of my stone walls, and then the portal disappear together with it. The Tannen's tower cannot use rod of teleportation so I'm stuck forever. Please fix it DarkGod.

Also, are there any way to keep that character and continue the game?

[Moasseman]

You can ask a moderator in the ingame chat/discord to teleport you out. Ya gotta be on the character that's stuck for us to send a prompt to you.