Wrong Thumbnail

[Wodkrah (Wodkah)]

Hey there!

After I import a panorama (exported as .dng) in lightroom, it displays the thumbnail of an old panorama I created some months back (sadly, not even a good one!). This problem persists through multiple restarts and different panoramas - it's always the same thumbnail. When I open the file, it takes around 3-5 seconds until it finally displays the thumbnail of the actual panorama. However, once I close the file, it swaps back to the wrong thumbnail. 

Any ideas on how I can fix this? It's bothersome since in an overview I can't really see what's what until I open it. 

Thanks in advance

Yannick

[PTGui Support]

Hi Yannick,

This must be a Lightroom bug, I have no other explanation. Lightroom is
caching thumbnails of your images and makes a mistake. PTGui can't embed
a thumbnail from a different project.

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

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[Erik Krause]

Am 19.09.2025 um 12:13 schrieb Wodkrah (Wodkah):

> After I import a panorama (exported as .dng) in lightroom, it displays the
> thumbnail of an old panorama I created some months back (sadly, not even a
> good one!).

What do you mean by "it", PTGui or Lightroom?

For speed reasons, PTGui first loads the thumbnail from the image file.
Calculating a separate thumbnail from the full-size image takes some
time. So if an incorrect thumbnail is displayed at first, it is
contained in your file, which would not be PTGui's fault then, but a
problem of Lightroom.

I assume that Lightroom does the same thing when you load an image
there. So if this panorama was created with PTGui and has not been
changed since then, there could be a problem. In this case, please make
the image in question available for download. Use Wetransfer, Dropbox or
similar for this.

--
Erik Krause
http://www.erik-krause.de

[Wodkrah (Wodkah)]

Erik, Joost, thanks for pointing me in the right direction. I've uploaded the panorama and a picture with the wrong thumbnail to dropbox: https://www.dropbox.com/t/ZF5Ptxjz3i6vGPl5

After reading your explanation I reckon it must be a Lightroom-Bug, which I will deposit there. By "it" I meant in Lightroom (non-classic). It only seems to happen with large panoramas. I've just checked and the same thing happens when I open the file in Photoshop / Camera Raw. It doesn't happen in other applications (PTGui,  Photo Mechanic,...), which leads me to believe it has to do something with my own catalog. 

Thanks again for your help, I will now turn to Adobe's support. 

Yannick