Some linked SVG files are lost when the afpub is opened again later. The SVG itself and the afpub are unchanged from when the image was placed (I use git file tracking, so I'm confident that both files are unchanged) and yet the SVG is not listed in the resource manager, despite it actually rendering when I first open the afpub:
Changing to another page and back again, the image disappears:
The outline shows that the image is still there and linked:
The transform panel for it shows an uneditable width and height of 0:
While the top bar shows what looks like more or less correct information about the linked image, except for the 0x0 pixels:
Adjusting the DPI or scale appears to have no effect at all.
Replacing the document with the same image results in wild DPI numbers that will not change regardless of what I set them to, it always resets to this negative number:
The only way to "fix" this that I've found is to completely delete the placed image control itself, then place the image again in the document. This works until it eventually breaks again at some point, and has to be "fixed" again.
Not all linked SVG images do this, only some of them. There seems to be no way to predict which images will do this - it appears to happen at random.