Hi.
I'm not sure what's going on, but it's weird for sure.
Throughout my campaign I unlocked various buildings and units, however when I can or can't build them is bugged.
I could have upgraded heavy factory on mission 4 even though I shouldn't be able to, because it brings nothing.
I can't build repair pads in tech levels prior to 7 (in other words missions 8 and later). I can build them on tech level 7 until I build light factories.
If I don't upgrade construction yard for a while, soon I won't be able to upgrade it.
On mission 7 I also couldn't build heavy factory once I lost all heavy factories, even though I had four refineries and multiple windtraps.
On tech level 6+ I can't build heavy factories once I build radar outpost. So if I lose it, I'm screwed.
And now comes the list of what I can't build, like, ever.
Starport and therefore IX research center and palace from buildings.
As for units: MCV, missile launchers and of course special units.
I'm not sure how or why it is happening, I haven't made any evil edits. It's a fresh download and install.