League Client Crushed

Evening Fellas, I had an Issue with my client for the last couple months, I wonder if someone has the same problem. this Issue happened to me twice but I fixed it with deleting the client and reinstall it back again, but for some reason when I tried to delete the client and reinstall, it didn't work for this time. Some times the client went all black and can't see anything, also the friend list isn't appearing for about 5 to 6 minutes.

If someone encounter this issue before help me out how to fix it please I'll be thankful.