I have pspace vports on defpoints layer (yeah, I know I should use a separate layer and use "noplot"...but old habits are hard to break).
I turned one vport off via on/off toggle under Properties>Misc. Now I can't see it (the border) to turn it back on. Hmmm...
MVIEW>On still prompts "Select objects:" , but I can't select something I can't see. I tried responding "All" but it also doesn't find the Viewport that is turned Off.
And yes, I have both Defpoints and Layer 0 on and thawed.
I opened a backup copy of the problem file (from before the Viewport became invisible) and recreated the sequence.
Now things are behaving like I expect...the border of the "off" Viewport is visible (modelspace contents are not) and I can easily toggle the Viewport On or Off.
So it may be just one of those random glitches in ACAD. I do think I'll stop using Defpoints as my vports layer; such a strange marriage of Defpoints and layer 0, especially when a dedicated layer with "noplot" is available.
Defpoints and Layer 0 go hand in hand. Defpoints won;t display in Layer 0 is off. I suggest that you create a viewport layer and set it to not print in the Layer Manager. That way you have full control over what it does, or doesn't do, and it will work as expected. I have always had issues using Defpoints.
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