While doing my daily playthrough of "Firewall" I encountered the two following issues that made me have to drop and restart the mission.
1) While defending file transfer room, two Terran enemies fell through the geometry outside the accessible part of the map. When I moved to the far right side of the map (out in the hallway ouside fo the room) I could actually see them on the mini-map off in the distance but could not reach them in any way. This made it impossible to complete the objective of cleaning up the remaining terran forces.
2) When I was unable to complete the objective to clean up the terran forces, I beamed back into space and re-entered the mission. The mission objectives matched the beginning of the "Warped" portion of the mission, but the map I was on was the Prime version of the starbase (in the darkened room where you initially meet Desoto).