Error= NOT a QUest

You know, this is very strange. (As I'm sure you have already figured...) But is this that kind of problem in which you go to click on a quest for download from the 'net, and a new window opens and displays total garbage in symbol form? Or is it... exactly what you said. because If it is the latter, my first piece of advice is to always make a backup under a kinda different name, then save back to the first quest. (In the middle of working on it, you save as under , say, PrinceD BACKUP, then save as PrinceD. Know what I mean?)

As to the former problem, I have had the same luck with the new SFX.dat. I couln't download it, and when I tried other methods, they turned out to not work! When I downloaded it (successfully) on someone elses computer and hard-disked it here, it was of a wrong format!
(In conclusion😊
Some people just have tough luck. We have to stick together in hard times, and the no-workie club is gonna stick together no matter what. So join the Club!!

Are you playing the quest with a higher or lower virsion to what you made it with?

Does it still load in Zquest? If not, you have a corrupt quest. :shrug:

Did you check to set the quest number to 0 in the quest header.
You can't load it in Zclassic with any other number

Dragonlord, quest number refers to is its 1st 2nd or 3rd quest and 0 being custom. Changing the number would only prevent playability, but not the ability to open it in zquest.

Sorry... but it IS corrupted...
I hope you have a backup!

Beta 163 has an autobackup feature that might help in the future.