gmod 3 days in a row saying game is curently unavailable please try again later

i am having a problem with connecting to gmod every time i try to use gmod it says this game is curently unavailable please try again later i have uninstalled and reinstalled it 5 times and it still says the same stuff for the third day now

Steam Community profile? Just to make sure it isn’t a pirated copy, GMod giving This game is unavailable errors is rather odd.
Try deleting ClientRegistry.blob on your Steam folder.

Restarting steam would probably help, if not submit a ticket to steam.