I’ve never seen this problem and I’m not sure where to begin looking to troubleshoot it.
I’m seeing a folder full of .tiff files (scanned negatives), but two of them are checkered over instead of seeing the thumbnail image. I had just edited these two files in GIMP and saved them as a .tiff file from there. Specifically, I had used the “Drop Shadow (legacy)” filter when applying a small watermark. The rest of the visible images are directly from the scanner.
Incidentally, I can re-open the .tiff file in GIMP, but can’t see it when I open it in Raw Therapee.
DigiKam 6.0.0 and GIMP 2.8.10 (Partha build). Thanks for whatever help you can offer.