Missing file: gr_cluster.model

Hi.

I am trying to set up a dedicated server (seems so be the only way to play with friends alone?)
I have followed the guide on wiki and a you tubevideo, seems fairly straight forward.
However.... when I start the server it stoppes at: Error: couldn`t open file "models/marine/grenades/gr_cluster.model"
I checked the folder and the gr_cluster.model is infact missing, I renamed another file to check if it was that file the server was prompting.
And I got a different error, so that file is just missing. What to do? I can`t seem to find just that file, and when I re-run server setup it downloads everything again except this one file.

Any suggestions ? Can I get just that one file somwhere?

Best regards.