by Claus Steiger.
Dear Ken,
Thanks a lot for your help. I have no access to the overall php.ini of the 1&1 server. I have therefore just created an own php.ini with the content extension=php_xmlrpc.so recommended by 1&1 (and not as you write extension=xmlrpc.so). But I do not know whether this difference is important. With regard to .htaccess: I have not found any .htaccess file in the moodle directories. Would it be possible to add a .htaccess just containing the line php_extension xmlrpc.so or php_extension php_xmlrpc.so or php_extension=php_xmlrpc.so?
Thanks,
Claus