got assignment edit page working again

Management.Web/Shared/Components/AssignmentForm/AssignmentForm.razor

@@ -34,6 +34,9 @@
   private string name { get; set; } = String.Empty;
   private bool addingAssignmentToCanvas = false;
   private bool deletingAssignmentFromCanvas = false;
+  private bool showHelp = false;
+
+  private void toggleHelp() => showHelp = !showHelp;
 
   private void submitHandler()
   {
@@ -157,9 +160,6 @@
     deletingAssignmentFromCanvas = false;
     StateHasChanged();
   }
-
-
-  private bool showHelp { get; set; } = false;
 }
 
 <div class="d-flex flex-column p-2 h-100  w-100" style="height: 100%;" >
@@ -170,7 +170,7 @@
   <section class="flex-grow-1 p-1 border rounded-4 bg-dark-subtle" style="min-height: 0;">
     @if (assignmentContext.Assignment != null)
     {
-      @* <AssignmentMarkdownEditor ShowHelp="@showhelp" /> *@
+      <AssignmentMarkdownEditor ShowHelp=@showHelp />
     }
   </section>
 
@@ -182,7 +182,7 @@
       </div>
     }
 
-    <button class="btn btn-outline-secondary mx-3" @onclick="() => showHelp = !showHelp">
+    <button class="btn btn-outline-secondary mx-3" @onclick=toggleHelp>
       Toggle Help
     </button>
     <ConfirmationModal Label="Delete" Class="btn btn-danger" OnConfirmAsync="HandleDelete" />

Management.Web/Shared/Components/AssignmentForm/AssignmentMarkdownEditor.razor

@@ -64,7 +64,7 @@
   private MarkupString preview { get => (MarkupString)Markdown.ToHtml(assignmentContext?.Assignment?.Description ?? ""); }
   private string HelpText()
   {
-    var groupNames = string.Join(", " , planner.LocalCourse?.Settings.AssignmentGroups.Select(g => g.Name));
+    var groupNames = string.Join(", " , planner.LocalCourse?.Settings.AssignmentGroups.Select(g => g.Name) ?? []);
     return $@"
 SubmissionTypes:
 - {AssignmentSubmissionType.ONLINE_TEXT_ENTRY}

Management.Web/Shared/Module/Assignment/AssignmentListItem.razor

@@ -98,12 +98,17 @@
         </div>
       </div>
 
-      @if(existsInCanvas && NeedsToBeUpdatedInCanvas)
+      @if(
+        planner.LocalCourse != null 
+        && existsInCanvas 
+        && NeedsToBeUpdatedInCanvas 
+        && assignmentInCanvas != null
+      )
       {
         <div class="mx-3 text-body-tertiary">
           @Assignment.GetUpdateReason(
-                  (CanvasAssignment)assignmentInCanvas, 
-                  Assignment.GetCanvasAssignmentGroupId(planner.LocalCourse.Settings.AssignmentGroups))
+            (CanvasAssignment)assignmentInCanvas, 
+            Assignment.GetCanvasAssignmentGroupId(planner.LocalCourse.Settings.AssignmentGroups))
         </div>
       }
       @if(!existsInCanvas)