I was running into an odd, game-breaking bug last evening.
It seemed like anytime a quest update instigated a conversation opportunity with a companion, I would suddenly lose all ability to initiate conversations with anyone. A couple of specific occurrences:
After defeating the nightmare creature in the Black Cove beyond the ominous gate, where you find Sam's collar, I proceeded to talk to the ghost related to the lighthouse quest just beyond that encounter. After the conversation, Madora had an exclamation mark above her head and wanted to talk. If I hovered my mouse over her, the conversation cloud icon would appear but clicking would do nothing. I used the rift travel to return to town and I couldn't talk to anyone there either.
Another time it happened was when killing Englander in order to resolve the orc feud quest. One of the companions got an exclamation point and the same issue described above happens.
The only workaround I have found at this point is to dismiss the companions before performing any quest related action that instigates a conversation with them and then go and pick them back up later.
DOS2 Mods: Happily Emmie After and The Noisy Crypt
