Thanks, Noctis. Yeah the bugged upgrade was the U-238 Shells for Marine range. It's patched now for Rebel Yell v1.3.
The decision to alter installation gameplay was not my own, but due to mostly positive reception, I can't argue with the change. Many people seem to like the concept and a few outright hate it. It's a fresh way to play the maps at the cost of the intense, tactical phases present in the installation scenarios.
I think I'll update the map in a future version to include both an RTS or TPS mode, along with some campaign difficulty throttling. Probably could work on the camera too.