Can't launch game, SteamStartup() failed

Hey everyone.
So I’ve just installed Black Mesa, followed the instructions, download the Source SDK Base 2007.
Every time Im trying to launch the game I get the following error:

“SteamStartup() failed: SteamAPI_Init_Internal failed”.
Screenshot:

I’ve tried to reinstall both the SDK and the mod multiple times with no luck.

Source SDK Base 2007 is in : C:\Program Files (x86)\Steam\SteamApps\common\Source SDK Base 2007

BMS is in:
C:\Program Files (x86)\Steam\SteamApps\SourceMods\BMS

Downloaded SourceSDK as well.

If it gives any clue, trying to run hl2.exe from the Source SDK folder gets the same error message, so I guess that means the error is comming from the SDK.

Any help will be appreciated.

Guess what, not 3 minutes passed, and a steam update was awaiting my resetting of steam.

2 minutes later, everything works…

HATE steam…

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.