KSP Interstellar Extended conflicts TETRIX Tech Tree by removing some nodes from the tech tree. The result is tree with broken pathways, nodes that lead nowhere, and missing nodes. And TETRIX nodes do not even appear.

Here's what tech tree should look like:
An here's how it looks:

did you keep your TETRIXTechTree inside the AngleCanMods? if not, put it there

This could also be an issue with using HideTechTreeNodes being installed and uninstalled.

Well I will add a rule just in case people put TETRIXTechTree in GameData

did you keep your TETRIXTechTree inside the AngleCanMods? if not, put it there

Yes, because I installed it by CKAN.

This could also be an issue with using HideTechTreeNodes being installed and uninstalled.
Yes, HETTN conflicts TETRIX Tech Tree, regardless if it is active or not.
Anyway, continue development.