@crashdown Heather: Yes, this is a scary bug. I’ve only had it happen once. Seemingly out of nowhere. I think it happened as I started up. No upgrade recently, etc. etc. Fortunately I only had one image to relink so the change in name was not a big deal. But for most folks it would be a nightmare.
I have no idea why this happens but it’s been reported before. I have no idea whether a solution is being worked on. Hopefully @tpbradley or @dan can let us know more.
The only sure fire way I know to avoid this is to NOT use resources. In the main that’s exactly what I do. This means first uploading your “stuff” (images, PDFs, etc.) to your hosting server via FTP software. (You could also do this via the Repository stack by @instacks ). Then you copy a link from each file (image, PDF, etc.) and use in your stack. Most stacks that work with images and other things have an option to use a link to a remote/warehoused file. Many/most photo gallery stacks allow you to point to a folder instead of one file so that makes creating galleries using this approach very easy.
If you have never done FTPing of your work to the server there’s a little bit to learn: but quite doable. And you’d have to find some decent FTP software like Transmit (paid) or Filezilla (free).
… however, before going down this road you want to make sure the stacks you use allow for remote linking. Many, but not all, stacks have this capability.