Hi Chris,
Thanks for your quick response.
Today I investigated the problem a bit further. Because it worked at my staging environment (not at production) I looked into the possible difference. I knew there couldn’t be anything wrong with server / code because those are the same. That’s why I looked into the database and… the table: ‘wp_3_gf_addon_feed’ wasn’t copied when duplicating the first site. It was missing. I created the table and now it works fine.
Sorry for bothering but anyway; thanks for thinking with me!
This is solved.
Regards,
Nick
