Error domain 1 code 4 on line 1 column 1 of file:///home/ray/Documents/Diagrams%20Sketches%20etc/120px-Triskele-hollow-triangle.svg: Document is empty

eog (Eye of Gnome, the image viewer) gives this error message when the .svg file you are trying to open is corrupted. If you have good reason to believe it is not corrupted and you are able to make it (or another file that produces the same error and which you think is not corrupted) public, then you should file a bug against eog in Ubuntu. First, you should make sure to read https://help.ubuntu.com/community/ReportingBugs carefully, and also to search to see if other similar bugs have already been reported. Then the best way to report the bug is to invoke ubuntu-bug with the PID of the running eog process (which should make sense once you've read that page), but you could also report it with "ubuntu-bug eog". Make sure to attach a .svg file that triggers the problem to your bug report. Also make sure that your bug report is complete and self-contained, so that it is not necessary for Ubuntu developers to refer to this question page to fully understand and appreciate the problem. Nonetheless, you should still associate this question with the bug using "Link existing bug" on this question page.

By the way, if the file is corrupted but GIMP or Inkscape (or another image editor) is able to open it, then you can save a new copy of it using that program, which might be openable by eog. If GIMP or Inkscape is saving .svg files with corruption, even if the original .svg file was corrupted, then that would be a bug in GIMP or Inkscape. (But if GIMP or Inkscape re-saves it and the problem still occurs, it's more likely not corrupted and a bug in eog.)