You beaut suv, Did you copy & paste the text (put on path) into a new document ? Or cut & paste it within the same document? This will put the path into the <defs> section unless it was selected together with the text object. To be honest I'm not sure what I did, but yes I probably did copy ...

Found the solution to my ALT key not working for select under
Kerning ([alt]+[arrows]) not working on Ubuntu Linux

You can set that under System > Preferences > Windows.

- specifically change the 'Movement Key' option to Super Key

Thank you Brynn, I hadn't discovered "A Quick Guide to Inkscape", nor did I know about selecting with the Tab key (much appreciated advise but sorry to report it hasn't helped with my problem of paths getting lost in the <defs>) so I'm continuing to learn about the wonders of Inkscape. BTW...

I'm having a problem changing a path after putting text on it. I create both the text and the path then use Text -> Put on Path afterwards I make the path invisible by setting Stoke Paint to 'No Paint' My problem occurs when I select the now visible text and Shift-D whereupon I get the message "...