Sadly, I have fallen victim to the same crash that seems to be impacting so many other players here. Even though the developers literally never respond to any contact and their support tickets also are never responded to I figured I would write up a bug report in the vain hope they might actually fix this problem so that I can play the game again at some point.

I have an extensive and deep survival mode vault, 150 ish dwellers, almost all full 10s in all stats, it has taken a huge amount of time to develop this shelter.

I am playing from a Samsung GS4, fully updated.

In my survival shelter my rooms are spread as a grid so that events cannot spread. I currently have the "survive X molerat attacks with no casualties" objective. Molerats attacked an empty, single space, level 1 room. When this event "ends" by way of timing out on an empty room the game immediately crashes. Unfortunately, when I boot the game back up, it is always roughly 1.5 to 2 seconds away from this crash. There is no way for me to send dwellers to fight off the molerats to end the event any other way, the crash happens immediately.

This is very, very frustrating. I guess there is nothing to be done but quit playing the game until/if this ever gets fixed, I am not going to start over another vault and sink this the stupid amount of time to develop a survival mode vault just to be caught with a boot up instant crash bug again.

Same problem here, it's still occurring as of this morning.

I hit this bug as well, but after about 10 attempts I was able to work around it. Here is how I did it. Load the game up, hit the menu button, select the objectives item and dismiss the molerat objective, if you have that option available. The event ends and no crash. Lost out on a lunchbox objective but better than an endless crash. It took a number of attempts as there is only few seconds to do that in, note that the objective has to completely clear before the crash can be avoided, took me a number of goes after I'd figured out where all the buttons were.