The interface changed a bit in SB 1.4, causing a minor error.

I added the same highlighting frame vanilla now has, thus fixing it. Plus I like the highlighting too.

• The requirements area is larger to display a longer "shortdescription" for your unlock items.
  
• This area and the unlock button are better centered for a better overall look. 1.0 was a little sloppy.
  
• The requirements area will now display the icon from your unlock items - and features automatic scaling in case you use larger/more detailed icons!
  
• Much better automatic pluralization of an item's "shortdescription" and also the opportunity to override this in the UI config ("Ancient Essence" already is).

• Player currency ("money", "essence", etc) is now accepted to unlock your techs. The UI would show it before, but it didn't actually work. Now it does.
  
• New "excludeSpecies" array option in "requirements". Does the opposite of "species". The intent is you could have one version of a tech just for a particular race, and another version for everyone else. You'd probably want to exclude the regular version for that race then.
  
• I was thinking there may have been some combinations of requirements before that might not have worked, but now I think they should after a little re-coding. The replacement code is also a little clearer.

Note I also added a couple example files to make clear how little you actually need to add in your patch files. One that covers you adding in your _metadata, and one that works without doing so (just a little extra patch work).