Hi David,
thank you for your reply. Actually there weren't any URL in URL View/Edit. So I decided to deinstall and install again.
And I fixed the error. He couldn't intall the JoomSEF Artio Plugin. So I installed in manually and now Artio is running.
BUT Artio is running with errors. Wehn Artio is active, I have on several places on my site the following text:
string(162) "INSERT INTO `#__redirection` (`oldurl`, `newurl`, `Itemid`) VALUES ('frontpage/rss.html', 'index.php?option=com_content&format=feed&type=rss&view=frontpage', '1')" string(164) "INSERT INTO `#__redirection` (`oldurl`, `newurl`, `Itemid`) VALUES ('frontpage/atom.html', 'index.php?option=com_content&format=feed&type=atom&view=frontpage', '1')"
So what is it? And how to fix it?