I cannot imagine that this adventure is working as designed because that would mean that the design was schizophrenic.
Where to start?
Well, first of all, this adventure requires you to use approx 800 gunpowder during the course of the adventure. It's available from level 42 but you can't actually produce gunpowder until you are level 47. Even then, if you don't have that much in stock, you cannot possibly make it in time before the adventure expires. A level 5 powderhut with a x4 buff will make 60 gunpowder an hour. If you're short by more than 240 and there's none available on the TO (which is common) then you have no choice but to cancel the quest.
Likewise you will need 10 spare settlers to create the Specialist buff. If you are at max population and have fewer than ten unemployed settlers, then again you can't complete the adventure without getting a lootspot to kill off some troops first (remember that you only have four hours at most to get that organised and pop the required settlers). You can also build some more housing but a lot of high-level players don't actually have spots available on their island for this.
The scenario buffs are inconsistent. Some are using the new slider UI, while some are applied like regular buffs and there's nothing that differentiates the two systems in either the quest text or the mouseover texts. When you are destroying the sabotage building, there's no way to tell in advance which buffs are usable against which type of opponent. The quest doesn't even explain how that works, you just have to figure it out by clicking on things until you figure it out. Once you do then the buffs you have are used more or less at random to destroy the various enemy types.
All in al, this adventure is a mess and should be considered broken.