At this page, the discussions tab is blank. The log shows that this is due to a null pointer exception:

[09 Oct 10:43:30 weblab] ERROR Something went wrong during var initialization of template template assignmentComments(assign : Assignment, showManagementDiscussion : Bool) [https://weblab.tudelft.nl/cs4200/2019-2020/assignment/24933/discussions]
[09 Oct 10:43:30 weblab] ERROR java.lang.NullPointerException
	at webdsl.generated.domain.AssignmentSubmission.addToCommentAuthors:919
	at sun.reflect.GeneratedMethodAccessor550.invoke:-1
	at sun.reflect.DelegatingMethodAccessorImpl.invoke:43 [https://weblab.tudelft.nl/cs4200/2019-2020/assignment/24933/discussions]

The code invoking addToCommentAuthors is in comments-view.app:372:

define assignmentComments(assign: Assignment, showManagementDiscussion : Bool ) {
    var comments := if(showManagementDiscussion) assign.managementComments else assign.comments
    // ...
    init{
      for(c in comments){
        prefetch-for c{
          author
        }
        c.submission.commentAuthors.add(c.author);
        // ...
      }
      // ...
    }
    // ...
}

Apparently the author for a comment can be null?

Submitted by D. Pelsmaeker on 9 October 2019 at 10:53