I've spent a large chunk of the day playing Return to the Path to Carcosa, and got up to scenario 7 - Black Stars Rise.
I was playing 2-handed with Daisy and Leo, until Leo was killed in the previous scenario (Charon's Obol has been powering him up, but then Daisy was defeated, and he was unable to complete The Pallid Mask alone, so was defeated during resolution), so I added in a Zoey as a second investigator.

Black Stars Rise was going ok, right up until agenda 2B advanced.
At this point, the scenario broke.
It instructed me to spawn beast of Aldeberan at the Abbey Tower (which was not in play).
Agenda 2C advanced. There were no clues left on the board, replacing the agenda deck with Act 3C.
At this point, I had not been able to get to Abbey Church, which required 3 clues per investigator to enter. Entering this location puts the locations required to win into play.
I was unable to enter this location, and there was no way to add more clues to the board (the Porte allos you to add clues, but only by moving doom between agenda decks, of which there was now only one).
I had to sit there and wait for the 3a to meet the doom threshold, and lose.
Frustrating to spend hours playing through almost an entire campaign, for the game to get into a state where it was not possible to advance, and the only resolution loses the campaign!

So, are you saying you spent all your clues drawing cards with the Agenda 1 triggers?

Having only played the original scenario once, when it first came out, I didn't recall how you needed to win, only that one of the agendas needed to complete for you to win - I was trying to make one of the agendas advance quickly. Of course the one I picked was the one that doesn't let you win, and says your goal is in the other agenda deck!

Even though that turned out to not be ideal strategy, the fact that the game can get into a state where it is impossible to advance seems broken.

The starting location has a mechanic that spawns clues

25 minutes ago, tsuruki said:

The starting location has a mechanic that spawns clues

Only as long as there are two agenda decks. When you get to the point that you have one agenda deck and one act, it no longer works.

Well, I guess you got stuck then. How did you manage that boardstate?

Are you sure you can't use that ability? Maybe the first part just does nothing (since it's not possible to move the doom as only 1 Agenda is in play) and then it just spawns the 2 clues for you anyway?

At least, I would probably play it that way to avoid an unwinnable situation.

If you've already advanced to Act 3 and haven't even revealed the Abbey Church yet, it seems pretty unlikely that you would be able to win the scenario anyway. We just played this scenario and got into the Abbey Church during Agenda 1a/1c and still lost (thanks Ancient Evils).

3 hours ago, Faranim said:

Are you sure you can't use that ability? Maybe the first part just does nothing (since it's not possible to move the doom as only 1 Agenda is in play) and then it just spawns the 2 clues for you anyway?

The second clause has a "then," so it only activates if the first clause resolves completely.

I don't think it's broken if you put yourself in a position to lose the scenario. I haven't played Black Star in a while, but from what I recall just pushing down one agenda is extremely reckless.

A resolution of "campaign loss" is my one criteria for replaying a scenario. Everything else and I'll just accept the penalties for a sub optimal resolution to see where the story goes. I recommend you also adopt that policy. It makes you way less gun shy about trying interesting campaign paths.