Cannot Create Preview Image

[RRbitwise]

Running XYplorer: 28.40.0400 (64-bit)
Windows 11 Pro Version 25H2 Build 26200.9711
Display scaling: 125%

For some PDFs, hovering the mouse over a PDF file name results in nice little preview pop-up. For other PDFs, hovering the mouse over that pdf file name results in the pop-up "Cannot create preview image".

An example PDF that successfully produces the preview: XYplorerHelp_V27.00.0700.pdf
An example PDF that fails: XYplorerHelp_V26_20_0200.pdf

The PDF viewer installed on the system is Foxit PDF Editor, Version 2026.2.1.39815
Foxit is the default PDF application on the system.

I have attached:
- The "XYplorer Various Information" data
- The metadata shown by Foxit for the two example PDFs I mentioned

Let me know what other diagnostic data you would like.

Thanks for the help.

[printersolved]

Not the dev, but a quick way to narrow this down: XYplorer's PDF hover previews come from the PDF thumbnail/preview handler registered in Windows (here, Foxit's), so the question is whether the handler or XY fails on that file.

1. Open the failing folder in Windows Explorer with thumbnails (Large icons) and the Preview pane on. If Explorer also shows a generic icon or a blank preview for `XYplorerHelp_V26_20_0200.pdf`, Foxit's handler can't render that file and XY can only report it.
2. Compare the two files' PDF versions/producers in Foxit's Document Properties. Older files saved with object streams or a different encryption flag are a classic case where a vendor's thumbnail handler fails but the full viewer opens them fine.
3. In Foxit: Preferences → General (or the installer's "Modify" option) has a setting for Windows Explorer thumbnails / preview handler. Toggle it off and on (or repair the install) to re-register the x64 handler. A 64-bit XY needs the 64-bit handler registered.
4. To test the handler theory, temporarily install another PDF preview handler (e.g. PDF-XChange's free shell extensions or SumatraPDF's previewer). If the "Cannot create preview image" message goes away for that file, it was Foxit's handler.

If Explorer previews the file fine and only XY fails, then it's worth the dev seeing your Various Information plus the failing PDF.

[RRbitwise]

Thanks for the reply.

Before I go into details, I want to state that I have resolved the
problem.

Your troubleshooting suggestions were quite helpful and they inspired me
to learn more about the mechanics of preview handlers in Microsoft
Windows.

Here are some responses to your first two points:

1. Windows Explorer has no problem showing the content for each of these
PDFs in the Preview Pane. However, when the Windows Explorer "Always
show icons, never thumbnails" option is unchecked, the display in the
Content pane (also referred to as the File/Folder listing area, i.e. the
pane to the right of the Navigation pane) shows a thumbnail with the
content of the PDF for XYplorerHelp_V27.00.0700.pdf and just a PDF icon
for XYplorerHelp_V26_20_0200.pdf. The choice of the icon size (Extra
Large, Large, etc.) has no effect on this.

2. The Properties for both PDFs were included in my original post. The
Properties for both PDFs look to be exactly the same (other than
reasonable differences such as file size, dates and the like). I also
extracted the Additional Metadata for both PDFs and, again, they look to
be exactly the same (other than the same reasonable differences).

The URL shown below gets you to Microsoft's documentation on the overall
architecture of preview handlers as well as guidance on implementing a
handler and system integration.

https://learn.microsoft.com/en-us/windo ... w-handlers

After reading through this documentation several times, I decided to go
spelunking through the Windows registry, examining the ShellEx entries
related to the PDF file type.

What I found was that this entry was incorrect:

[HKEY_CLASSES_ROOT\.pdf\ShellEx\{8895b1c6-b41f-4c1c-a562-0d564250836f}]

This entry defines the Windows Shell Preview Handler Interface for the
PDF file type. Microsoft's Windows Explorer (and presumably XYplorer)
examines this key to find the actual previewer to be used for PDF files.
The value of the (Default) subkey item of this key is the CLSID for the
preview handler to be used.

What I found was that the specified CLSID was:
"{DC6EFB56-9CFA-464D-8880-44885D7DC193}"

This is NOT the CLSID for Foxit's PDF Preview Handler; the Foxit value
is "{1B96FAD8-1C10-416E-8027-6EFF94045F6F}". A web search revealed that
the errant CLSID is for the Adobe PDF Preview Handler.

The Adobe Acrobat program product had been previously installed on my
system, but it was uninstalled prior to installing Foxit PDF Editor. It
appears that the Foxit installer failed to properly update the Windows
Registry. I verified that the Adobe PDF Preview Handler itself is not
present in the system.

I used Regedit to modify the Registry value to contain the correct CLSID
value and rebooted Windows.

EUREKA ! PDF previewing now works correctly in XYplorer and Windows
Explorer.

I will interact with Foxit so they can address the root cause of the
problem with their installer.