Do you have a recent save you can reload and try the approach again? Depending on what the problem is, maybe doing something different will get it to work (leading with a main character rather than companion/henchman, etc).
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 (so keep your latest save and the most recent one before that encounter, at least)).