Anyone else have a problem with the oil platform mission?

[Mr Luberman]

I've made sure that topside is clear of bad guys before I lead him up. But as soon as he starts walking up the steps to go topside he dissappears. I sometimes get a message to place the satchels, so I think he might have made his own way there. but he's not there. & I can't get the other hostage as he's not appeared. Also when I bring up the misson obj. free the 1st hostage is not complete & it doesn't bring up the obj to free the 2nd hostage.