In Content Export documentation it's referred that BulkPath needs to be configured. The suggested value is extension/ezrecommendation/design/standard/images/ . The trailing slash (/) is not needed, since eZRecoInitialExport::getXmlFilePath also adds the slash.
Also note that eZRecoInitialExport is defined in ezeecoinitialexport.php (not the expected ezrecoinitialexport.php file - an "r" has become an "e"). Consider if the file should be renamed.