错误未捕获异常'RuntimeException'

Question

In my error log I founds thousands of this:

Joomla Version 3.3.6

PHP Fatal error: Uncaught exception 'RuntimeException' with message 'Duplicate entry 'http://www.dualda.de/index.php?option=999999.9' //uNiOn//aLl' for key 'idx_link_old' SQL=INSERT INTO ade39_redirect_links, referer: http://www.dualda.de/

Any idea?