Single Line SVG files are NOT for cutting.
They are for use with WRMK Foil Quill & Pens.
To use these files you need to change the settings to DRAW instead of cut in your software.
If you have Cricut Maker these files can also be used with the Deboss and Engraving tools, you need to select the file then change the settings to deboss or engrave in design space.