a.l.e. & Garry,
Thank you for spending the time on this problem. I have a question about the "Collect" option.
The collaborative workflow with my partner is we both contribute different artifacts (text, pdf, pngs, etc.) to the source sla file (in Dropbox) from the various folders within our shared Dropbox environment (image attached). We both have access to the same sets of artifacts. If I do my work on my Mac, bundle everything up with the "Collect" option, will she be able to contribute by adding new artifacts from our other shared dropbox folders. If so, this will be the answer to my problem.
I think Garry is correct about the path issue between OS X and Windows. When I add a new pdf in the sla file from my Mac, and I then open the sla file from my Windows machine, the image frame looks empty, but it really isn't. When I double-click on the frame I get a window that pops up with a frame and a large red X in it with the correct name of the file it is supposed to pull into the frame. Below the frame is the path C:\Volumes\Macintosh HD\Users\rcb\Dropbox\My Private Files\Scribus\TH Song PDFs\100-199 (image attached). It knows what is supposed to display, but its path is to my Mac. What's weird is I can see all of the images, not matter who updates the sla file, on my Mac. It is only a Windows problem.
The reason I believed the problem to be Ghostscript related, is that I had this exact same behavior between the two Windows machines when I was first setting up the workflow. I would create the document ready for publishing on my Windows 7 machine, but my partner couldn't see the pdf images on her Windows 10 machine. The problem was fixed when I loaded the Windows 10 machine with a 64 bit version of gs9.09. The same behavior occurred when all three machines were loaded with gs9.22, so I think Garry is correct about the file path. I am not sure how to fix that, but it seems like it should be a simple thing to do.