Viewer pane displays PDF only if I move frame edges with mouse

I used to have no problem viewing PDFs with the DO Viewer Pane, but now when I select a file and hit F7, it shows PDF Xchange is loading, but one loaded no image unless I grab the viewer pane edge and move it.

Running DO 12.22 & PDF Xchange Editor Pro 8. I have the same setup on my laptop and no problems, so maybe I will need to bite the bullet and uninstall/reinstall, but thought I would ask

PDF XChange is not part of Opus.

Presumably the same problem happens if you view PDFs in File Explorer's viewer pane using it? If so, the issue would need to be raised with the PDF XChange authors, rather than us. Or you could switch to a different PDF viewer (assuming there isn't an update to PDF XChange which fixes it).

Actually, I did not have that problem in Windows File Explorer, but you were too on top of it for me. I checked for a later build on PDF Xchange Editor Plus 8 and installed it. Now things are back to normal. Should have thought of that first. Sorry. I think Tracker does not automatically update its software, which could be a good thing. The new build is 343 on the off chance that someone else runs into this.