"The symbol could not be imported. The template version number must be present in the SVG file. Make sure that the version number text has not been converted to outlines."

I encountered this error aswell only to realize whenever you export svgs from Figma, text turns into outline. The solution is using Illustrator to save template svgs. If you prefer using Figma to design icons, you can export the icon svg and place it in Illustrator.

I've just spent 30 minutes banging my head against this and found the solution (in Figma at least), in the export panel beside SVG you have some export options. Check 'Include "Id" Attribute' and uncheck 'Outline Text'.