Client Freeze/Crash

Hello, and to whom it may concern, I have been experiencing a very weird and recent glitch or bug. When I would start up league, everything would be fine. When the client login pop up would begin, the typical ivern or worlds animation would not load, I could not type or login whatsoever, and the client would crash completely. This happened for 4 days and I was not able to log in whatsoever. Any thoughts or advice if this were to occur again?