Lots of people have had issues recently, so I figured I’d make a topic helping out anyone that was having issues. I apologize if this has been posted in it’s own topic previous to me making one, but it’s always good to have new topics at the top to help people. I would try leaving the Steam beta in the Steam application (If you use it for GTAV). Look at the top left of the Steam application, go to Steam/settings/account and opting out of the Steam beta client in the bottom. Maybe this will work for you, maybe not, but I figured I’d help if I could.
A little issue that I have run into is worth mentioning here. When I opted out of the Steam beta, I was surprised to find that all of my games needed an update. The only problem is that this wasn’t a “verify game cache” update bug, it wanted me to re-download ALL of my games that were already INSTALLED on my HDD and SSD. I have seen a few fixes on Steam support discussion topics such as:
https://steamcommunity.com/discussions/forum/1/135508031951816809/
or
https://steamcommunity.com/discussions/forum/1/684839199046901613/
but none have helped me. I would subscribe to these discussions if you’re having the same problem as I and hopefully a fix comes out soon. If you don’t have this issue (a large majority) then consider yourself lucky.
Again I apologize if this was posted elsewhere but I figured I’d try to help since I saw so many posts. Hope this helps you 
Thanks,
Mason