there are no "errors" on facebook - don't listen to that notification

repeating it here for more permanence 'cause FB wall posts disappear into the ether rather quickly

Everyone should ignore and block "Facebook Error Check System." 

http://josh.my/2009/02/beware-spyware-facebook-application-called-error-check-system/

if you already allowed it,
1) under Settings (upper right side)->Application Settings, click it and then in the list, click the "x" of the app.
2) change your password, just in case

oh, and keep an eye, 'cause apparently you may accidentally have given it the rights to come back even after it's been x'ed out.