Material Editor issues

The material editor does not keep any of my edits, the window just goes away and when I reopen it every thing is gone.

Did you switch preset by any chance? Each preset comes with it’s own material settings.

I have a soundstage space with aan anchor desk that I’m trying to light. When I’m working in the material editor to create light sources the window will suddenly go away along with the edits. How do I save the changes along the way?