Tried to make a custom tech tree. Just wanted to change some names. No new techs. Made 3 new files and put them in a mod, TechSpecializationDefs.xml, TechDefs.xml, TechDefsText.xml. Put the first two in the Game folder and the last one in an English folder. Game crashed on starting and new game. In a last effort put them into the regular game files. Still crashed. Redid the files a couple of times looking for errors. Same thing. Can a custom tech be created? Is there more to it?