Mastery Page Load Failure

Just wondering other peoples thoughts on changing a mastery page after everyone has picked their champs only to have it not load into the game thus being... well "out of luck". I just lost my promos because i chose to leave the game so my team could remake rather than putting them through a game i may have no chance at. I changed the masteries with around 3-5 seconds left and it just loaded with none... happen to anyone else?