While playing the scenario of "Secure Research Facility", when I get to the last group and get killed, when I respawn the group is gone and I can not complete the scenario. I have walked around the entire complex and can not find them.
I have had similar problems with this in the volanis sector, and a version of the mission in the Arcurian Arm.
My intital suspect was the "Defeat enemy squad" objective followed by "Defeat all enemy squads 0/3." While I did have to respawn in the Arm version, I simply had no "third" squad to defeat in either case. That's four expected squads in total according to the objectives, and only 3 squads spawning in.
As a side note, did you notice you had lost the ability to enter "aim mode?" It occured to me on both missions.
Same issue in the same mission, and submitted a bug report.
Also, in a different mission, where you beam down to a planet and have to defeat 5 squads of Klingons, my away team was wiped and I saw, as the last member fell, the remaining Klingons in the squad "beam out". I ran back to make sure and they were gone. Some sort of bug that triggers on a party defeat.
And yes, on many missions in Delta Volanis, I could not use C as well.
Yeah, it seems apparent that toggling crouch/aim isn't global for ground missions like it should be. Even if there are no enemies on the map and the mission script doesn't call for one, you should ideally still be capable of crouching even if it's completely unnecessary. Especially since you can toggle crouch/aim at Earth Spacedock and lord knows that'll never see combat.