XYplorer Beta Club

I have two issues:

My PDF preview only appears to work against certain pdf files and I am not sure why. Some will display the thumbnail and others will show "Cannot decode"

For PDF previews (that I can get to work), how do I change the size of the preview? Is this a function within my PDF viewer or XYplorer? I've tried different PDF viewers and they all produce the same very small size PDF preview.

There are quite a few threads on this forum about PDF preview, which a search of the forum would reveal, however, for me the solution was a combination of the "PDF XChange Editor_v10.3.1.387" and the "PDF XChange Viewer_v2.5.322.10" installed in this order and make sure to set the Viewer to be the standard for PDF previews. This gave me big previews in the file list, while still being able to use the Editor for its advanced functions.

I only have installed the PDF-XChange Editor 10.3.1 387
This works in all places of XY.
Preview Pane
Floating Preview
MDBU in File list
Thumbnails