Ozaru 2 models

[Mellon90]

This is the Ozaru model by VALKEMIERE, needs to be fix in many animations because during various actions the model disappears totally.I don't know why if i import the model, i can see him in the editor, and also in the game, but if I close the map and try to opend the same map there will be a crush.I can only avoid the crush with import, save and 1 play test, if you miss the try, there will be a crush and you will not be able to open the map again.However this is a unsicure method because the model need to be fix anyway. i Have also the Ozaru of BARDACK (Valkemiere)with the same animation problem ,but works perfectly.Can someone help me?