I was palying the albania mission. I smashed every enemy building and unit(clickable) in the misssion. There is a objective 5 "produciton facility" markers over a totally blasted parking lot with nothing to destroy, so I can't complete the mission. Any sugesstion would be helpful.

Oh, well i solved the problem by restarting the game at the point, when the bridge was due for repair.
The reason for the bug was that if one shoots the barrel and destroy some of the vehicles before the announcement of the final objectives(destroy nod supply depot). It will create a conflict between triggering of yellow markers on the places of already destroyed vehicles.
In my case, the group of vehicles damaged by me become unclickable and undestructable. Hence the game will not allow me to completely fulfill the objectives even if you throw everything on the suspicious marker spot.
So do not wait after crossing the bridge and head straight to the reinforcement bay to get final objective announcement.