Very very big problem!

I'm afraid not.

What happened?

If it did it while you were in zquest just dont save the quest, leave zquest, then go into zc again to see if that fixed it.

Unless i'm missing something.

I played my game in ZC and I notice bug. When I go to Zquest to fix it, problem appeared.

Two questions.

1.) Which version are you using?

2.) Did you change the number of maps your quest has by accident?

I seem to recall that if you lower your map number it deletes all the maps after that number, so perhaps when you tried to go to a map you clicked map number instead and ended up erasing your maps. Hopefully you can remedy the problem if you have a backup version of your quest or if you didn't save it when this happened.

If you're using 2.10, I don't know if that map number thing still applies because I haven't moved up to that version yet.