The problem is that in one of the older versions I had an art tag using small plot size for the building but large for the wonder, making no space for the wonder to be built.
Edit: Fixed. I had a problem with art tags. So, if you ever make a building, just remember you can't "plug in" any <ArtDef>, because they come in two different sizes. If you have a small size for building 1 (normal town building) then upgrade to something with an <ArtDef> that is bigger (like a farm, or crystal trove) it will give problems...
I fixed it, and will be uploading another pack soon, but I want to get some other things done before uploading the second pack. Thanks for reporting the trouble so I could fix it!
The second pack will contain horses, wargs, metal, hit point per turn, exp for stationed units, mana shards and other things. still working out the balance issues, but your feedback helped me eliminate the <ArtDef> problems, thanks for your feedback!