Can't play Gmod, any help please ?

Hi, i bought Garry’s mod today and when i try to play the game the loading get stuck at ‘‘iniatilizing serverside’’ so… i can’t play the game…

Please help me.

Cordialy Tomha2

PS: i tried to allow the security in microsoft fire wall and it doesn’t give anything.

Have you bought any other source game?, because I cant view your steam profile