ForceAdvanceQuest will only advance the quest past the dream itself and not past talking to Caldara in the tree.
NPC_Caldara isn't available to add to the party or interact with at all after being removed from the tree.
However if you want a quick fix you can use these console commands-
This will give you the ID for your player (most of the time it will be Player_(YourMainCharacterName) but other times it's Player_New_Game(Clone)_0 for whatever absurd reason).
AddAbility yourplayerID crucible_of_the_soul
This will give your hero the watcher ability he would have received at completion of Visions and Whispers.
This adds 501 experience points for talking to compensate for not being able to talk to Caldara in the tree. The quest line awards 249 for having the dream and 501 for speaking to Caldara for a total of 750 combined exp at quest completion(at least from my solo player experience, not sure if this value is different with companions).
This will start the next critical_path (story) quest that is normally received immediately after completing Visions and Whispers.
Essentially by running these console commands you will have received everything you would have by actually completing the quest. If you were like me and decided to avoid resting the first time until even after Lord of a Barren Land's completion then you could either increase the AddExperience 501 to 750 to allow for the 249 received from the dream portion or use ForceAdvanceQuest data/critical_path/act_1/cp_qst_becoming_watcher.quest to advance the quest past the dream cycle and receive your exp that way. I say this is a temporary fix because, as with any game-breaking issue that is publically announced, a fix will eventually happen to prevent this, remedy this, or just cover it up in extra code. What this means for people who use this method to fix it though is that we may possibly be awarded the exp for completing the quest later or have some negative effect from whatever fix that is deployed. Hopefully their fix will include a check though to first see if the Old Watcher quest has been started and, if so, just mark the Visions and Whispers quest as already completed (without reawarding exp/skills again or attempting to rehash up the Old Watcher quest lol).