Thank you all for taking the time to respond.
While I appreciate your suggestions regarding converting clips to avoid duplicate filenames and timecodes, it does not explain my situation where I have reduced my sequence to a single clip. Just one. So there are no duplicate files or timecodes. But when I try to import the timeline XML into Davinci, it says media not found.
I am able to import the same media clip directly into Davinci Resolve, and drag it into it’s own timeline in resolve and everything is fine. But when I try to import a Premiere Pro sequence (containing only that clip) as an XML file it can’t find it. When it asks me if I want to find it manually, I point it to the correct folder, but it still can’t open it, and the red “media offline” icon appears instead. It’s driving me crazy!