cmodelloader:map_isvalid no such map "map name"

[Bobbish]

Anyone know what this means? The maps appear to load when I load them, and they seem to work fine. It does not appear to be stopping them from working, but it is filling up my console with this message. What does it mean, how can it be fixed.

Also, I should note that these are not custom maps created by myself, they are downloaded from filefront. They should work?

Any ideas on how to fix?