TD-4893 Delegate activities - view course delegates resulted in 500 error when course admin field applied filters got deleted

Author: sherif-olaboye

DigitalLearningSolutions.Data/Helpers/FilteringHelper.cs

@@ -170,9 +170,7 @@ public static string GetFilterValueForRegistrationPrompt(int promptNumber, strin
         public  static  string? CheckIfFilterisValid(bool clearFilters, string existingFilterString, string newFilterToAdd, IEnumerable<FilterModel> availableFilters, HttpRequest request,
        string cookieName, HttpResponse response)
         {
-            if (!request.Cookies.ContainsKey(cookieName) || string.IsNullOrEmpty(request.Cookies[cookieName]) || clearFilters)
-                return null;
-
+            
             var cookieValue = request.Cookies[cookieName];
             if (string.IsNullOrEmpty(cookieValue) || cookieValue == EmptyFiltersCookieValue)
             {

DigitalLearningSolutions.Web/Controllers/TrackingSystem/Delegates/ActivityDelegatesController.cs

@@ -275,7 +275,10 @@ public IActionResult Index(
                 var activityName = isCourseDelegate
                     ? courseService.GetCourseNameAndApplication((int)customisationId).CourseName
                     : selfAssessmentService.GetSelfAssessmentNameById((int)selfAssessmentId);
-                existingFilterString = FilteringHelper.CheckIfFilterisValid(clearFilters, existingFilterString, newFilterToAdd, availableFilters, Request, filterCookieName, Response);
+                if (!string.IsNullOrEmpty(existingFilterString))
+                {
+                    existingFilterString = FilteringHelper.CheckIfFilterisValid(clearFilters, existingFilterString, newFilterToAdd, availableFilters, Request, filterCookieName, Response);
+                }
                 if (isCourseDelegate)
                 {
                     var result = paginateService.Paginate(