GAME ISNT UPDATING

So i try to open lol and whenever i open it it shows me the following messege(WE HAVE RESTORED THE INSTALLASION TO AN OLDER VERSION OF LEAGUE OF LEGENDS.NOW WELL TRY TO PATCH IT UP TO THE LATEST VERSION.)after that i click okay then it writes a nother messege(THERE WAS A PROBLEM PATCHING LEAGUE OF LEGENDS WELL RESTORE A BACKUP VERSION AND TRY UPDATING AGAIN AFTER U RESTART THE PATHCER.)i dont know what to do i clicked restart multiple times nothing happens same messege again and again i restarted my pc nothing happends if anyone know what i ahve to do pls tell me.Also it entered one time and it said (there was an error 404) please help me