Problems with the sounds of shots. (Garry's Mod)

Help me please! After installing CSS content, weapon firing sound disappeared in Gmod. With some types of weapons, this problem is not (with a pair of laser cannons and weapons of the Second World War (from a separate add-on). There are no shot sounds for standard guns and for firearms from different add-ons. I went to the game folder, to the sounds folder. All sounds are in place , the files are not damaged (you can even listen to it) .However, there are still no sounds in the game. I tried to remove the folder, start the game without it and then close the game and put the folder back in place. It did not help. Reinstallation of the game did not help. What to do?