Adding an SVG as a wiki logo causes problems#581

When selecting an image for the wiki logo, SVG images are available in the file-dialog to select, but choosing one will name the SVG wiki.logo, but not treat the result as a logo.

Instead, it will show up in the sidebar as a file called “wiki.logo” that will not load, and if another logo is selected (e.g. a PNG), it will create a second file called “wiki.logo” in the root of the Drive folder. One will be used normally as the logo, while the other shows up as a file.

Deleting the extra “wiki.logo” seems to fix the problem.