Game stops working when i receive mission during champion select

when i get my mission during the champion select it bugs and doesn't let me choose any champion , it always shows me that my team needs to choose a hero ,but they never do and instead it remains in the champion select at 0 seconds, still working on , but can't do nothing, after i close the Game I receive a "leaverbuster" because of this bug , and I swear that I don't want to get this anymore.

some help would be nice:(