I lost my tech tree

[Undecided]

For some reason, the core/vanilla tech tree just up and vanished on me. I can see all new, additional tech nodes that were added by my various mods, but not the core tree itself. And the tech nodes I can see all have a tooltip of "no text". If I pull up the alt+f12 and use the cheat console to max out techs, the missing parts of the vanilla tech tree appear (though scattered all over, and not connected or located as they normally are).

I've tried deleting the techtree config file for the mod manager (didn't help), running a steam file verification to replace any modified core game files (also didn't help), and even tried installing tech tree mods hoping to overwrite the damage/missing tree (also didn't help).

I'm kind of at a loss on how I can get my core techs back without deleting everything and doing a brand new install. What file(s) govern the vanilla tech tree, and how can I fix them?

[Nansuchao]

Probably the best solution would be to move your save elsewhere and reinstall KSP. meanwhile, what mods are you using?