i have been unable to move users in mumble since the latest update 1.2.3-506-gf4da625 (1.2.3 Developer Snapshot). i run murmur on a router using umurmur. it hasn't been a problem until i updated today.
We had a regression that broke drag and drop for Windows clients. It got fixed by a recent commit so the issue should go away with the upcoming snapshot.
Please reopen this ticket if it doesn't.
5fdf6e2 Fix drag and drop regression introduced by Qt updated.