I'm trying for the 3754254274th time to make a mod for my Star Adairis campaign, and i've run into the most absurd and STUPID problem yet.
So I copied a bunch of Protoss buildings and changed them to make a new race, most of the structures WILL NOT construct, they will be placed down and stuck on 0 progress and (whatever health they started with)
Here's the most annoying part.
The structures that were based on the:
Pylon
Assimilator
Nexus
Work fine, all the others (about 8 or 9)
have the aforementioned issue.
I'll try my best to advise but I haven't run into such a problem before.
Potential problems:
-method of building (Zerg method, Terran method, or Protoss method)?
-Animation (did you change/fiddle with the building animations)?
-Do structures appropriately have Requires Psi (not) checked?

I do stuff and thingies... Try widening and reducing the number of small nooks and crannies to correct the problem.
Make sure the building has the "Build in Progress" ability.