[urgent error] error message " ue4 trying to simulate physics but it has complex collision as simple

need help, UE4 show error message “UE4 try to simulate physics but it has complex collision as simple” i make a tunnel mesh (in blender) with some obstacles inside it, i use complex collision as simple with customized collision as my collision setting. But when i run the player inside the tunnel, i dont hit my player to any obstacles or the tunnel itself , just fly along the tunnel hole, and suddenly my plane character destroyed / damaged without hit anything (fyi, it just fly along the tunnel hole and didnt hit anything).
please explain me why this happen and solution for this error. thank you!