I just made a Garry’s Mod server a couple days ago and it’s working fine, and addons seem to work properly as well. I went to add a Grand Theft Auto Online game mode that I found on Steam (This is just one of them, there are multiple packages you have to download: http://steamcommunity.com/sharedfiles/filedetails/?id=224883082) and extracted the multiple packages with gmad extractor. I then put all of the files into one folder called grand theft auto online, and put that older in /garrysmod/gamemodes. I also tried murder just to sdee if it was the gamemode, and murder didn’t work either. Thanks to anyone that tries to help me. Also, if anyone knows where I can download an official Grand Theft Auto Online gamemode (unless this one is the official) that would be great.
[editline]21st August 2015[/editline]
I’m also working on re-extracting the files and putting it the gamemodes to see if I messed up or anything.