For Advanced Mass Emails, an error "Server Error in '/tracking' Application. The length of the URL for this request exceeds the configured maxUrlLength value." is received when clicking a link that has tracking enabled. In tests and previews of this template, the link works correctly.
This can happen if the URL entered in the hyperlink is not complete. The link must have http:// or https:// (depending on the website) at the beginning of the URL in order for tracking to work correctly.