there is a mistake in the config file for tech tree for that part which means it isn't appearing in the tech tree in career mode.
If you edit this file (with any text editor) /GameData/Endurance/Parts/ENDURANCE\mountEndurance.cfg
Change:
TechRequired = experimentalRocketry
to:
TechRequired = heavierRocketry
I'll update it in the next version.
there is a mistake in the config file for tech tree for that part which means it isn't appearing in the tech tree in career mode. If you edit this file (with any text editor) /GameData/Endurance/Parts/ENDURANCE\mountEndurance.cfg Change: TechRequired = experimentalRocketry to: TechRequired = heavierRocketry I'll update it in the next version.