If you find a bug in a 52°North Geoprocessing software component, send an email to firstname.lastname@example.org. Once it's confirmed as a bug, someone, possibly you, can create an issue at the respective projects page on GitHub.
Some older components are not on GitHub (yet). For those you can still use the 52°North Bugzilla.
To register for the Bugzilla, you have to create an account at the 52°North Wiki.
The login name for Bugzilla is your WikiName.
The URL of the Bugzilla is: https://bugzilla.52north.org/describecomponents.cgi?product=52N Web Processing