STUCK ON AUTHENTIFICATION

Hello guys. Since yesterday i have encountered this problem. I came back from my military service and wanted to relax with my best friend. When i put my info and press "sign in" it is stuck forever on authentification. I have restarded my pc huntdred times. I have unistalled and reinstalled 3 times now. I have used the Hextech repair tool. Nothing works. I see that this issue occured 2 and 3 years ago. Is it because of the Patching or whatever it is updating. Anyways I would love to get some help about this issue. Thanks.