I have done my simulation by motion analysis (moving like ball and socket in 3 seconds ) by  2 parts of assembly which should be giving me the final results during 3 seconds; after 1 second all 2 parts and also S-S curve are disappear and I could not find them.

when I checked their position in part lists they are change to hide and they shown as HIDE parts. 

These 2 components completely mated and fixed however I put more mates to make sure they are not moving (unless in desirable path) and I also change their properties of materials and also change the materials as well.

I have done all different methods but still problem not solved.

can you help me please.

Thanks