I have a maxed out vault with 200 dwellers, 12 currently exploring. the number of raiders coming to attack is 4 and soon after the second raider is killed the game crashes. my exploring dwellers can not be recalled and they continue to add time, but the rest of the shelter is pretty much stuck after the crash... there is no other progress except for the dwellers in exploration... many have died but can't be brought back since there are only few seconds of allowable activity before the game crashes. I am able to create other vaults, but this one game is my best run so far. I have also purchased lunchboxes into this particular vault so i would hate to delete it. specially since i have 8 of the legendary dwellers unlocked so far.