Those maps are not broken. The message you got is supposed to occur only under very specific conidtions: If someone has digged out a treasure at the very same position but the guardians of it are still alive.
However, this is currently not working and leads to the following problem: If there is ANY active treasure, no matter where, you cannot dig out any other treasure. So there can only be one active treasure at a time.
That will be solved with the next update.