The first problem I don't think I've seen reported before. I've dismissed party members a few times in the Hall of Heroes without any issues.
Please email supportdos@larian.com, with a description of the problem and the report.zip file generated by the
D:OS support tool (for the PC version). The report will contain system and game information, any crash dumps, and your saved games. If file size is an issue, any saves not related to the problem can be deleted; at least keep a save where the north gate is fine and then then next where you have switched henchmen and the game will crash, and if any saves in the Hall of Heroes are more likely to crash when dismissing party members you could leave one or more.
