You receive this error when we don't know exactly what's wrong.
First, try logging in at http://profile.surfconext.nl/ Does that work? Then SURFconext is working and you were able to reach your institution. This means something is wrong with the connection between your institution and the service you are trying to reach: it's best to contact the helpdesk of your institution directly.
Otherwise, contact us at firstname.lastname@example.org and send us a screenshot of your error (comparable to the picture up there). Make sure the Unique Request ID is readable. Also tell us where exactly you are trying to log-in and what institution your account belongs.