@Developer: I missed this because if you search through the settings for "pdf", for some reason this setting page doesn't show up...
Can this be remediated?
Thanks for getting back to me.
I think (?) I have that setting enabled (see below), but XnView still just shows my pdf's like an image if I double click on them.
My default pdf-viewer is Acrobat.
Is there some other place where I have to tell XnView to use Acrobat?
This is just a checkmark...
Checkboard setting under Settings > View ("Use checkboard pattern as background") does not respond.
Setting is turned off, but Checkboard pattern still appears in file & folder list.