installed on drive D, steam sees it but doesnt launch

I have two hard drives on my PC and installed steam and the mods on drive D: steam sees the mods but wont run them. HL2 and all other games work fine.

I also got another mod, but that one doesnt work either, same issue. I am guessing that the drive path is not being passed correctly? how do I fix?

BM doesn’t have a set drive path. I’ve got Steam installed on my E: partition, and all my games including BM work perfectly. Do you have the Source SDK along with with 2006 & 2007 Base packs installed, and run each of them once?

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.