That mission is hit and miss.
As this mission is one of my pet peaves, I will say this. Either get rid of the Behemoth as an essential link to enter the door, add a key card that you get from the stupid robot after you kill it to fix the door glitch, or add a secondary manner to enter the door using a stealth (hack) option. There is a glitch that is failing to tell the door (in code) that the dumb robot is dead!
Ultimate answer .. GET RID OF THE STUPID ROBOTS!
Hey,
Is this for the mission "Stop Walker's plan"?
Also is this the issue: https://www.youtube.com/watch?v=XRTG...ature=youtu.be ?
If so I may need to ask a couple more questions to investigate this
Thank you