Hi.
Firstly, I had problem with finding any information about SVG files in Glyphs Mini handbook. From other forum posts I assume I can import SVG by drag&drop or by pasting.
I tried with multiple files – created by myself (Figma) or downloaded from the internet. The simplest file I gave a try looks like this:
I tried drag&drop, paste and Add Image. Everytime in the glyph edit view. Each time I got red text (not a dialog or something) Image Not Found: file-name.svg. Pasting PNGs works.
Yes, glyph edit view was active, nad after your question I tried with many tools active – same result all the time. Do you need some screenshot or recording?
Can you put the file on the desktop or the download folder and make sure you can open it in Preview or any other image app. Then put the .glyphs file next to it and then add the file to the edit view?