CS:S models appearing as errors

I feel kind of stupid for saying this but…
I was recently making a ‘Crysis’ type map in hammer (lots of trees, lots of bushes ect…) and I found a two really nice props that fit my landscape perfectly. The two models are:
However; when I compiled at looked at them in-game, they both appeared as errors. I was wondering if it was just my map, so I put them in a test room and compiled again. Both were errors again. I was wondering if anyone knows a solution? And just because I know someone will ask for the compile log; I can tell you already that I have looked at it and there are no errors.