Добавил обработку пустых запросов

PaydayFrontend/Models/University.cs

@@ -0,0 +1,10 @@
+namespace PaydayFrontend.Models;
+
+public class University
+{
+    public long Id { get; set; }
+    public string Name { get; set; }
+    public string FullName { get; set; }
+    public string ImageUrl { get; set; }
+    public long MinPlaceCost { get; set; }
+}

PaydayFrontend/Models/UniversityDirectionsViewModel.cs

@@ -2,6 +2,18 @@
 
 public class UniversityDirectionsViewModel
 {
+    public UniversityDirectionsViewModel()
+    {
+    }
+
+    public UniversityDirectionsViewModel(University university, List<Direction> directions, string searchString)
+    {
+        University = university;
+        Directions = directions;
+        SearchString = searchString;
+    }
+
     public University University { get; set; }
     public List<Direction> Directions { get; set; }
+    public string SearchString { get; set; }
 }

PaydayFrontend/Models/UniversityViewModel.cs

@@ -1,10 +1,13 @@
-namespace PaydayFrontend.Models;
+namespace PaydayFrontend.Models;
 
-public class University
+public class UniversityViewModel
 {
-    public long Id { get; set; }
-    public string Name { get; set; }
-    public string FullName { get; set; }
-    public string ImageUrl { get; set; }
-    public long MinPlaceCost { get; set; }
+    public UniversityViewModel(List<University> directions, string searchString)
+    {
+        Directions = directions;
+        SearchString = searchString;
+    }
+
+    public List<University> Directions { get; set; }
+    public string SearchString { get; set; }
 }