Save's Not Working?

I try to load up a save and it always bring’s me back to the main menu. I open the console and it says this:

“Save file SAVE\half-live-100.sav is not vaild”

I’m trying to load a save I downloaded off of Gmodfiles.com

Oh, and the map is gm_snabbansairfield

Save has been broken a while now, older saves dosent work on newer gmod too i think

They’re outdated for the G-Mod.