[2019] "Missing File Privileges"

Perhaps a solution for you can be found in one of these posts
https://steamcommunity.com/discussions/forum/1/1458455461474727488/

https://steamcommunity.com/discussions/forum/1/1474222595297633271/

unfortunately this happens from time to time with steam for some users.
I haven't had it happen to myself for a long time though.