Error: You need to save the animation in project`s assets file folder - but I`m trying to save in project`s assets folder!

Hi! Im making simple 2D game in Unity (version 2020.1.0a21.2690 with Unity Hub). I want to make an animation, so in the Animation window, Im clicking “Create” button, and selecting a folder (**projects assets folder!**), and then, Im getting an error:
171305-obraz-2020-11-20-074813.png

and I can`t save the animation.

Anybody knows the answer? Please help!

Make a folder inside the assets folder and then save the animation that folder you created @orkork435

Ok, I copied project files from D: disk to C: disk, and now Its works, so now Im closing question. Thanks for help!