I was beginning to mod the tech tree, and struggling, and then noticed I was in the wrong file (TechDefs.xml).
What's the difference between these files.
Another oddity; I was able to get a tech to show up for my modded race, but oddly it's not shown in the Tree View. Is there a separate action I must perform to get it to appear in the tree view. It's odd that the tech would be available to research on the research screen, but not show up in the Tree View at all.