I'm way beyond that stage and experienced no such bug. It could be your installation, but then again you may have done something unusual prior to this which is causing a conflict with the area transition. Only a theory but how many quests have you completed in Cyseal and have you completely explored the map. Everyone plays differently in terms of quest order / exploration so maybe it was something specific to your actions. Could be a rare bug hard to cause. Also is your party together when you try and cross the bridge.