The red ERROR occures everytime a model in a map is missing.
This usually happens if the model was in the asset of beta 1 but is erased or renamed for beta 3.
In that case recompiling the map for beta 3 won't solve the problem, coz they are still missing.
Adding them to the beta 3 model and texture folders won't help too, coz the editor will see they are EP1 props and won't list them.
A simple solution, pack them into the .bsp, somehow the engine is just checking models which are in the folders, packed content won't be checked for the version number.
Missing textures (black-pink checkers) can be also added to the bsp.
BUT, in most cases the light will be very bright and HDR is to bloomy and if the map got a Ladder forget it, the ladder will not work in Beta 3.
So i suggest you to wait for the mappers to port their maps to beta 3, maybe they will take the chance and improve them a little, too.
And if the mapper won't do it (e.g. he has no time anymore), ask him if you could do it.
