diff --git a/WebApp/Components/Features/Calendar/Import.razor b/WebApp/Components/Features/Calendar/Import.razor
index 569b508..9163457 100644
--- a/WebApp/Components/Features/Calendar/Import.razor
+++ b/WebApp/Components/Features/Calendar/Import.razor
@@ -155,6 +155,7 @@
                             .SelectMany(list => list)
                             .Select(eo => eo.Location)
                             .Where(loc => !string.IsNullOrWhiteSpace(loc))
+                            .Cast<string>() // Cast to non-nullable string after null check
                             .Distinct()
                             .OrderBy(loc => loc)
                             .ToList();
diff --git a/WebApp/Components/Features/Calendar/Index.razor b/WebApp/Components/Features/Calendar/Index.razor
index 32882d6..3d593ba 100644
--- a/WebApp/Components/Features/Calendar/Index.razor
+++ b/WebApp/Components/Features/Calendar/Index.razor
@@ -110,7 +110,9 @@
                     }
                     
                     // Get student first names for this event definition
-                    var studentFirstNames = StudentFirstNames(occ.EventDefinition, teamsByEventId);
+                    var studentFirstNames = occ.EventDefinition != null 
+                        ? StudentFirstNames(occ.EventDefinition, teamsByEventId)
+                        : new List<string>();
 
                     var calendarItem = new CalendarEventItem(occ, studentFirstNames);
                     items.Add(calendarItem);