I took as example the Hardened Bunkers for a curious detail. If we look the Obsoleted Items and Upgrade Options sections below, the Hardened Bunkers make the Basic Shelters obsolete and upgrade the Heavy Bunkers:

<Building Key="MINOR_HARDENED_BUNKERS">
<TechRequirements>
<BioTech>4</BioTech>
<Energy>5</Energy>
<Computers>4</Computers>
<Construction>5</Construction>
</TechRequirements>
<BuildCost>3260</BuildCost>
<IsUniversallyAvailable>false</IsUniversallyAvailable>
<Prerequisites>
<EquivalentPrerequisites>
<Prerequisite>MINOR_BASIC_SHELTERS</Prerequisite>
</EquivalentPrerequisites>
</Prerequisites>
<ObsoletedItems>
<ObsoletedItem>MINOR_BASIC_SHELTERS</ObsoletedItem>
</ObsoletedItems>
<UpgradeOptions>
<UpgradeOption>MINOR_HEAVY_BUNKERS</UpgradeOption>
</UpgradeOptions>
<EnergyCost>25</EnergyCost>
<Restrictions>
<Restriction>OnePerSystem</Restriction>
<Restriction>HomeSystem</Restriction>
</Restrictions>
<Bonuses>
<Bonus Type="PercentGroundDefense" Amount="20" />
</Bonuses>
</Building>

In the picture below, the Obsoleted Items and Upgrade Options sections don't appears. It is a bug? (it's the same thing for the other (only) races minor structures such Combat Grid, Heavy Bunkers etc...)

That's odd. I can't see anything wrong in the code above the image that could cause this to happen. I guess Mike will have to look into the cause.

Odd...

This structure is a minor race buildable structure, and both it's upgrades and prerequisites are minor race structures too. None of these structures are included in the Empire build lists though. So that must be what has happened. These structures were intended to be for minor race defence against attack, and I didn't think that the build list could be affected when said minor race joined another empire.

If I add these structures to the build lists of the empires though, that would mean the Empires would be able to build them in their own systems. Do you know of any way around this problem, Mike?

*Edit - I just discussed this with starfleet.command. The NonNativeSystem restriction might be able to do what we need. He's going to test it.

If it's a minor race structure, then it won't show up because of a bug. I'm working on it this week. Don't add them to the empire's tech tree.

I haven't really touched the files since the editor stopped working, Mike. That's why i've been compiling a list of fixes that need to be done instead, ready for when the editor works again. I'll leave this out until you say the game is ready.

Mike & Matress, in my demo, for the minor races structures who's got the prefix MINOR_ and the minor shipyards, i put them in:
<IsUniversallyAvailable>true</IsUniversallyAvailable>
and replace:
<Restriction>HomeSystem</Restriction>
by
<Restriction>NonNativeSystem</Restriction>

They appears now on the minor race system & in the encyclopedy.