Why do my objects go away when begin play?

Hey Guys, I have a problem about the level. When I place a mesh (no matter from me or the default objects in UE4 level), it is there, but goes away when I check on physical stimulation. I have checked KillZ in world-setting but it does not help.

When I add a radiance force into level, the mesh goes away like with crazy large force. When I set the destruction damage to 1, it does not work, but it goes crazy to be 1.5 or 2.

Did anyone meet this problem before? Thank you so much.

Try to increase the mass of the actor (under Physics) or reduce the forces that are applied to it. See if that makes any difference. If you have an actor with a very small mass and you apply a large force to it, it will get a large acceleration and fly away almost instantly.

Also check that upon spawning your actor does not collide with something in the level which could apply forces to it. For example, that your actor is not partially sunk into the floor.