I can't finish the second part of the mission - Big Bang Theory (destroy three tanks patrolling the street and then go to the Retired Gray Colonel's Estate).

After destroying all tanks I came to the Estate... And nothing. I tried to enter from all possible ways (also tried to walk to any of the grey flags), nothing.

At all my attempts one tank always goes into the hangar (when chasing me), where it's stuck and destroying the hangar should kill also the tank... But I'm starting to think if it's not the source of the problem?

In the first part of the mission - Beware the Air - there also seems to be bug with resquing your team - even when I kill all gray troops around the building, green troops never appear.

Is there any remedy/workaround for this mission?

Ok, after another attempts (lost count how many :P) I've found out, that indeed the tank destroyed inside the hangar was blocking the completion. After making a lot effort to destroy all three tanks normally (bazooka, mortar), there was triggered green truck and mission continued.

Phew, finally finished that game, first time I've played it around 2001/02 and never finished it due to incredibly hard mission 4 in Desert.

thanks for posting the answer