XML editor toolbar icons appear disabled and show with "x" image

XML editor toolbar icons appear disabled and show with "x" image, but they still function and the rollover highlight and tip text works. So not a big deal once aware of it, but confusing at first as it seems like certain nodes can't be deleted or operated on. However, trying to use the buttons anyway everything seems functionally ok.
The "unindent", "move up", and "move down" work normally but the rest don't show properly for any selected node.
Attached screenshot shows observation.
New documents i create show all the XML editor toolbar icons normally, so i have an example doc that shows the error and one that doesn't when opened in the same version of Inkscape (which is version="0.92.1 r15371", 32bit install on windows 10 pc).
So it's definitely something different between the two documents but i couldn't tell what was out of the ordinary from the text itself.