Welcome to the forum!
After some research, Acorn appears to be a photo editor for Mac. Since Inkscape is a vector graphics editor, and a photo editor usually edits raster images, they might not be compatible. Or if they are, the contents coming from Acorn might be raster contents, and therefore not editable in Inkscape.
I don't really know if we can help, since we don't have many who use Macs here. But we'll try
But the first thing we would need is to look at is the SVG file which comes from Acorn. Can you also show us a screenshot of the image in Acorn, so we can have some idea what's supposed to be there?
If nothing else, and it's photos that you're working on in Acorn, you might just skip acorn, and import the photos directly into Inkscape. But a LOT depends on what you're planning to do with the contents, and what your ultimate goal is. Would you please share as much as you can about that?
