Fixing 500 error for real

Services/LocationService.cs

@@ -58,6 +58,9 @@ public class LocationService
 
     public virtual async Task AddItemToLocationAsync(string locationId, string itemId)
     {
+        if (!ObjectId.TryParse(locationId, out _) || !ObjectId.TryParse(itemId, out _))
+            return;
+
         var idFilter = Builders<Location>.Filter.Eq(l => l.Id, locationId);
 
         // if the Content array is null, initialize it first
@@ -71,6 +74,9 @@ public class LocationService
 
     public virtual async Task RemoveItemFromLocationAsync(string locationId, string itemId)
     {
+        if (!ObjectId.TryParse(locationId, out _) || !ObjectId.TryParse(itemId, out _))
+            return;
+
         var filter = Builders<Location>.Filter.Eq(l => l.Id, locationId) & Builders<Location>.Filter.Ne("Content", BsonNull.Value);
         var update = Builders<Location>.Update.Pull(l => l.Content, itemId);
         await _locations.UpdateOneAsync(filter, update);