I just got the bloody game 10 mins ago after finding me phone which has been lost for 2 months. Anyway it launches fine I choose a vault slot then a vault number then it gives me all this [censored] about keeping my dwellers happing but while its loading the app closes and takes me back to my main phone screen. I'm using a huawei ascend y50

I had this problem on my android. So i checked program properties and saw that it is saved on phone memory AND SD card. So I moved FalloutVault to phone memory only. And that somehow did the trick.