Reference: You have entered an invalid ad id
For reference, if you are getting the error below, by clicking from the Dashboard list of ads (Edit Ad) - if you have tried everything you can think of and you still get the message:
""You have entered an invalid ad id or do not have permission to edit that ad"
Then try this out.. check if the ad has been 'started'. There is the weird double-relisting process needed in Classipress (I DO NOT KNOW WHY?) but if you 'Relist' you have to click Start as well.
If you haven't clicked Start, well, it's not a live ad, and for some reason currently can't be edited! (D'oh).
Yes, this means that a user can't edit an ad first, then send it live, thus meaning if there is wrong information.. the ad has to be live with the wrong info and get edited. Annoying.
Hope this helps someone, I was really scratching my head.