Sumatra PDF is a PDF, ePub, MOBI, CHM, XPS, DjVu, CBZ, CBR reader for Windows

Using SumatraPDF to preview CBZ/CBR in Directory OPUS

Basically SumatraPDF work very fine and fast viewing PDF, CBZ/CBR, EPUB and others
Now I want to integrate it into DOPUS (Directory OPUS)
There is a function where I can have a preview panel to view the file without opening the program.

SumatraPDF generate an entry in the ACTIVEX viewer which work fine for PDF.

With this config, I can view PDF files in the preview panel. But CBZ, EPUB just show an icon.
Then I decided to add the extensions to this config.

Then now PDF still works, and CBZ or EPUB show a GRAY screen instead of the icon.
I understand there is something to do differently.
¿May anybody help me on this?

The “Pre-viewers” other than PDF are not active in a public release.
They work fairly well with most eBook covers but for example may not show ALL CBRar5 covers.

They can be added by installing a SumatraPDF developer version however
If only needing those CBZ (ZiP) and ePub (Zip) covers it may be just as easy to load other previewers for those similar formats. CDisplayEx / CBXshell and their grandchildren clones can usually build THUMBNAILS only (Not quick/pre-view) You could look at recent GitHub - dark-knight404/DarkThumbs: Thumbnail preview for EPUB, CBZ, CBR, RAR and ZIP image archives which ads CBR but do read about the currently known issue with multi-file.epub and I also had some cbr5 files not showing

Dare I mention potentially the best serious solution is to try Mystic Thumbs (circa $35) 14 day FREE fully functional evaluation so no commitment to give credit card first.
Like SumatraPDF it uses GhostScript but unlike SumatraPDF it uses that for (.AI .PDF .EPS .PS etc.) thumbnails and previews. It currently has better CBR support, but apparently none for FB2.
There are many SumatraPDF formats it does not support and vise versa

Personally I am happy with the default MSedge PDF & TXT previews as I use portable and they are the only 2 formats I need to quickly skim read pages without opening them.

OK. Thank you very much for your suggestion.
Interresting comments. I finally found a plugin allowing CBZ, and CBR thumbnails.
I have PDF with sumatraPDF
Compressed files are managed OK with my Digital OPUS file explorer
then I have to find one for ebooks (epub and others)
Thanks again