My League won't update to 4.20?

So as everyone knows, with we all have to download the new 4.20 patch. However, my game does not seem to download. It will go up to 86%, and then drop to 0 KBps. I've tried uninstalling it and re-installing it, but every time I try, it will (without fail) stop at 86%. Any ideas on how to fix? Thank you.