Glad to hear it works.
My current guess is that when you load the original images (in your very first module "LoadImages"), the image paths are well kept in the final SQL table, and can be correctly loaded.
If during your pipeline, you generate new images (here are those "CellOutlines"), although you saved it in "SaveImage" module, but the path and location where it is saved wasn't written (or somehow wrongly written) in the SQL table.
If you're keen on testing this idea, we can do this experiment:
- Run your pipeline first time, and save some "CellOutlines.png"
- Run your pipeline second time, now at the first module "LoadImages", load the newly saved "CellOutlines.png" as images, name them something like "NewlySavedOutlines".
- In the "ExportDatabase" of the second run, select the thumbnail with "NewlySavedOutlines"
Let's see if it can display.
I'll think of a more elegant solution... But let's see if that's really the case.