Error:anyone got a fix?

Black Mesa Archive In-game Issues (Mod)
#1

Every time I launched BM I got this error, and when I tried to launch source SDK base 2007 it gave me the same error:

MountAppFilessysystem() failed:
SteamMountAppFilessystem(218,0,0x1 c3ef5c4) failed with error 1: No
default filesystems for this app

Please help :’(

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.