I did a screencast in case it is helpful in any way to see what was going wrong. As that includes about 4 minutes of absolutely nothing happening, I figured I would not record all subsequent attempts.
After this repeat of my failure (had failed about 5 times previous to me recording to report), I tried uploading the puzzle without the image: That worked fine, got a 30 minute approximation.
I then tried once again with just the image engrave enabled (all other steps ignored). This I had tried before, but I figured it was worth another attempt, as the entire project is not worth doing if I cannot get the image in place.
This time it DID upload and allow me to start cutting/engraving it. Only 40 minutes too, which should have tipped me off to the problem. I left it set up with 1,000 for speed. What I really want to do, and had done in the above recording, was 200 speed.
I having the 1,000 speed engrave running right now, and it looks dark enough I may stick with what I get instead of running a second pass, not sure. I will update this post with another attempt to upload the 200 speed engrave.
Best guess for why it wasn’t uploading would be that the time required was too large maybe? If it needs 40 minutes at 1,000 speed, then it should have wanted nearly 4 hours at 200 speed. Is there a limitation on total time per individual job?