REAL time preview stopped working? appearing.

[Ron Kramer]

I'm fairly new to PI - I get things done, I've processed awesome images. But occasionally due to my lack of knowledge  stupid things happen.

In this case - I was trying to learn more about masking. Somewhere in my example - my real time preview stopped appearing.  I can click the button (lights up or off - but no preview appears).
I suspect it's been told to be hidden?   how do I retore it?

[Ron Kramer]

I clicked show preview and still nothing.

[Ron Kramer]

Solved - I leave my machine on for days on end without reboots.  I went to reboot pixinsight and it wouldn't reload. I rebooted the machine and PI loaded and preview is working again so was windows run amok.