"Well mostly the trainer works like a charm..as every trainer i get from here But i DO have some weird problems. If i activate all options on the trainer occasionaly my hud dissapears in missions and also waypoints to where i am supposed to go.
I can just reload and it is back working fine again."
I get the same thing, but it really only happens if I'm way too close to a grenade. Either thrown by the enemy or myself. Game thinks you are dead, yet you live on. I've been able to push on and complete the mission without the waypoints or HUD. It's quite linear so eventually you'll get to the end. Although you could miss some access points along the way.