I'm the server administrator for our WeBWorK 2.16 instance running on Ubuntu 20.04. When I'm in a view within the Homework Sets Editor such as:
and I try clicking the "eye" icon on any problem to "Open in New Window" (where that link would be of the form https://<my server>/webwork2/admin/arc-length/2/?effectiveUser=admin )
Then I get the error attached, which says "No display module found for path '/admin/arc-length/2/'. at /opt/webwork/webwork2/lib/WeBWorK.pm line 161."