UE4 does not save my files!?

This is driving me mad, Unreal engine 4 simply does not save some files. mostly my animations.
I import a model with animations, setup a blueprint and all, save my project close it open it up and the model is there and the blueprints and all that. but the animations are always gone.

Sometimes it helps to remove the character completely and remake everything, but this time it didnt help, one specific animation does not save.

I get this message every time it cant load it up:

Very happy for help.

When you are done with the project, don’t just hit save project in the bar above the editor screen. Don’t rely on autosave. Hit every file you notice disappearing and right-click save. On each of them. I had the same problem, but this helped. Good luck.