Recoverable fatal error

I got this message when I pressed save at http://localhost/admin/config/people/accounts

Notice: Undefined index: xmlsitemap in xmlsitemap_link_bundle_settings_form_submit() (line 1315 of C:\xampp\htdocs\sites\all\modules\xmlsitemap\xmlsitemap.module).
Recoverable fatal error: Argument 3 passed to xmlsitemap_link_bundle_settings_save() must be an array, null given, called in C:\xampp\htdocs\sites\all\modules\xmlsitemap\xmlsitemap.module on line 1315 and defined in xmlsitemap_link_bundle_settings_save() (line 993 of C:\xampp\htdocs\sites\all\modules\xmlsitemap\xmlsitemap.module).