I'm not sure this is a bug, however I have reinstalled my game twice and it still occurs (And i've tried different save files).
After applying the patch, my Act 4 saved games can no longer go to Battlefields. Not because they can't warp there... but rather once there, they can't warp out. They just respawn inside battlefield on the spawn spot.
It's no big problem, because at this late a stage they aren't really needed, just wondered what causes it. It is a little frustrating however, because I wanted to check out the Battlefield 5 quests from the merchants.
I've noticed when selecting the battlefield 'skill' icon (as in the button on the right of portraits) when I warp there it says "Enter Battlefields - Level 5". When I try to leave the Battlefields it says "Leave Battlefields - Level 1". It's all pretty strange.
Anyhow just wanted to post this in case it's all related to the other battlefiend problems since the patch. Everything else within Battlefields works fine though, spawns are fine etc... I just can't leave once there.