Unreal Engine for Aximmetry force close problem

I working with Unreal Engine for Aximmetry, and UE always automatically close if I hit Play button or when I try to open one of my Level Sequence. I also tried to delete this Level Sequence (because I think this sequence is too heavy), but the program will close when I click delete on the keyboard. There is no error message after closing, can someone help me with this issue? Thank you.