Help pls

Whenever there is a patch update I have to uninstall then install back lol. It used to run smoothly but now it doesn't. When there is an update it says a required update is gonna happen automatically in 10 secs. That's fine but it doesn't patch update. Then I click on lol again it says an older version of league of legends has been installed pls update this. But it doesn't update. The number disappears as well. So I have to uninstall then install it back. Pls fix this riot.