Hello, I've run into two issues recently in which something I've done has prevented main quests from advancing.

1. In the Old Church, I originally had Wolgraff use walk in shadows to press the buttons behind the paintings and open the stairway down. He was carrying a teleportation pyramid, and the rest of the party teleported past the enemies in the church. I spoke with Thelyron but decided I wasn't at a high enough level to fight Braccus yet. I went back upstairs, and when the encounter triggered the casket covering the stairs closed. I didn't think anything of it at the time, but I've come back after advancing pretty far on other fronts, and the buttons no longer open the stairway - I can't get back down to fight Braccus. It's quite a bummer as I'm unable to complete some main quests as a result.

2. I ran into something similar with an encounter in Hiberheim, but it was more obvious something had gone wrong and I was able to reload right away. In the encounter with the Conduit I had a character with a few items that boosted his already-high telekenesis score grab the blood stone off the table while the Conduit was talking. When the conversation ended she and her followers all just stood there. They were invincible when attacked and took no actions. I also couldn't use the blood stone to regain any parts of the tapestry, and when I dropped it from my inventory there was no way to pick it back up. (Again though, I just reloaded when I realized I'd broken things.)