KSP doesn't create any new savefiles

[Morgueço]

So... my game just doesnt save animore.
I have gone to the entirety of minmus's biomes, and i'm in my way on mun's biomes. got 3 there and im comming back to kerbin. but my game doesnt quicksave, neither when i go "esc - save game - save" nor "F5".

And at any autosave events (like returning to KSC midflight or entering the tracking station) just doesnt proceed.
I can load games just fine, but the game just doesn't create a save file (autosave, manual quicksave or f5 quicksave). What is happening?

 

[EDIT]: all the addons are fine, up-to-date, the rest of game is working just fine regardless this unique issue of creating savefiles

Edited June 16, 2018 by Morgueço

[Chel]

Have you been tampering with any of the game files? I'm talking about folders other than GameData and Plugins.