Chapter 7 Dallas’ Rig Missing, Can’t progress. (Find the admin rig)

I had this problem as well, but I somehow got it to spawn. I changed my usual resolution of 1920x 1080 to the next lower res (1768x 992), then I reloaded my latest save, which was the save station just before the zero gravity with all those asteroids that needed to be cleared. I hope this helps!