We really took into consideration your multiple complaints and reports about people using bugs. You ask and we deliver. We made a tough decision to launch an automated dungeon reset system sooner than we planned. From now on, every time you try to save a dungeon, it is checked on server side and gets validation if it is possible to complete.
It will decrease the bug user number dramatically. However, there is a probability that some very tough dungeons will suffer the same measure and will be reset to defaults. In this rare cases, players also get 'Please stop use bugs' kind of message. We're very sorry for that. We continue working on polishing of the script.
PS Old dungeons are being checked and reset gradually.