Campaign mission: The Horns of Hattin fails for no reason

I have no idea why the mission fails. It constantly stops and says that I have failed. I don’t have the keep destroyed (enemy is not even close), the hero is alive, what else?
I recorded a video and I still don’t know what’s going on…

Any clues?
I found corresponding save file if it matters. The fail happens in around 10-30 seconds after the save. Unfortunately I cannot upload it here.

I cannot upload AOE4 .sav file here, so I put it on google drive:

It’s 70MB, didn’t know that AOE4 save files are that big…

Try to put the troops forward and prevent the Franks from reaching the circles…

Shouldn’t the circles be used to burn the grass? The mission specifically says that I can burn the grass once, which means I have to retreat after the grass is burned once. This is very confusing. The castle is intact, why the game says I failed to protect it? I can try to fight at disadvantage, but this is clearly a bad scripting.

Yes, same thing, it’s strange…

I’m not sure but I think that it involve with star on the north, at second ambush location before able to build army.

Game seem to register that no enemy unit close to the goal city on East that have star or mission failed, but seem to have issue that there is star on north and enemy on north reach the star.

Try anything to remove the star, even burn grass at that location, or make sure to kill all enemy reaching that star.

You are right. Look like I destroyed the second wave without moving my spearmen in that position and the trigger didn’t happen. I was kinda surprised that the enemy knights stopped and didn’t want to go to the fire, so I have to attack them and lure into the fire. It turns out I had to put my spearmen into that position instead to make the knights moving. That’s explains the glitch. Thanks a lot!

Yes, the campaign is very scripted, so it is likely that it can be glitched more easily…