I just try the flyme 3.1 but its china rom, the features so great and so light since it is china rom the usage of memory is not that great so that i thought thats the cause of very light and smooth compared to the global rom that uses google services, the AI maybe wrongly defragment or freed the memory that cause the app to crash i think the point of all.this problem.is just ram 2gb ram is not enough to run the flyme system, features and the the google services.