The last 2 days, my game is constantly crashing in the forgotten tower while trying to farm keys from the countess. It will be the instant I click on a tower level, not always the same one. I’m playing single player on Switch.
I wonder if it is similar to the issues around the dark woods and underground passage not spawning a dark woods exit in D2R. If this is happening on a single player map, try loading up the character on OG d2 and see if it still happens. It might be that the map isn’t spawning one of the exits and causes the game to crash.