The devs announced that they had to delay the patch in order to fix a serious issue with the new instance: “As we do with all updates, we continually test until it goes out the door. From this testing we discovered a critical bug with the Crisis on Umbara flashpoint. This bug can prevent a substantial amount of gameplay when a player experiences it, from not playing the intro cinematic to not allowing re-entry into the instance. Due to the severity of the bug, we are not comfortable releasing the game update in its current state.”
Update 5.4 is now scheduled to deploy first thing Wednesday morning. The silver lining to all of this is that the team has lowered the cost for the Umbara train stronghold from two million down to a much more reasonable 5,000 credits.