Gah! Need major help fast! (I know, I ask too many questions)

I tried to load my quest in ZC, and it said ERROR NOT A CUSTOM QUEST in the large box underneath the file box.(You know, you hit "A" twice and a po-up appears, a smaller box above a bigger box in the same window, when you choose a file it gives the information there). It sais that in the boax, and the "OK" button is greyed out so I can't click it. HELP!