Warning message

Hi, I recently got the following error message when validating a file:
Line 7, Column 23: This validator does not validate Inkscape extensions
properly. Inkscape-specific errors may go unnoticed.

xml:space="preserve">

I would like to make it so my file doesn't show this warning, but nothing
from the description of the warning enables me to do this.  I tried removing

xml:space="preserve"

from the file, but that didn't work.  I tried removing

xml:space="preserve">

from the file, but that didn't work either.  I tried removing the entire
section above this within the <>, and that caused a failure.  I am not wiz
at inkscape and do not know to excise "just" this piece of code (I am
creating in Illustrator and converting to SVG and making my edits in
Notepad).  It would be handy if something about the error suggested how I
might be able to make it go away.  Just a thought.  Thanks.