Ok, I’ve given you a bad link. This link has a download link for Joakim Söderberg’s fork, and I’ve just installed v1.2 and had joy with the save button. The correct one looks so:
and the one that doesn’t work so:
After setting the file name and using the … button to choose a folder, then the ‘Save’ button at the bottom of the SVG Export dialog gives this:
I’ve just gone through the sequence of installing the bad one, failing to save, then disabling it, applying that change, quitting Sketchup, downloading the v1.2 file, back in Sketchup Extension Manager installing the new one, and saving an .svg file.
I’m sorry I wasted your time with the bad link. I’ll go back and edit it out of my post to keep others from wasting their time.