Hello @regnvandstanken,
As far as I can see I can’t find anything wrong in item 0001 in the feed or with any condition.
I assume the warnings where from the Google report? Easiest is to contact Google Support in your country (they usually are very helpful) and ask for more information. Or at least tell us what more information the report gave you. Normally the report has a bit more information about “what or why” something is not accepted.
I did find three products though that have no id (“Hvirvelfilter til regnvandstank – 500 m2”, “Hvirvelfilter til regnvandstank – 3000 m2” and “Hvirvelfilter til regnvandstank – 200 m2”). Could be that the source you chose as id for these articles is empty?