Fixed an issue that prevented saving attribute values

Fixed an issue that prevented saving attribute values

Author: valadas

Settings.ascx.cs

@@ -1454,16 +1454,24 @@ private void lbAddAttribute_Click(object sender, System.EventArgs e)
             }
         }
 
-        private void lbAddValue_Click(object sender, System.EventArgs e)
+        private void lbAddValue_Click(object sender, EventArgs e)
         {
             DotNetNuke.Security.PortalSecurity objSecurity = new DotNetNuke.Security.PortalSecurity();
 
             if (lstAttributes.SelectedIndex != -1 & !string.IsNullOrEmpty(txtNewValue.Text.Trim()))
             {
                 RepositoryAttributeValuesController attributeValues = new RepositoryAttributeValuesController();
                 RepositoryAttributeValuesInfo attributeValue = null;
-                int _key = int.Parse(ViewState["_key"].ToString());
-                int _index = int.Parse(ViewState["_index"].ToString());
+                int _key = Null.NullInteger;
+                if (ViewState["_key"] != null)
+                {
+                    _key = int.TryParse(ViewState["_key"].ToString(), out _key) ? _key : Null.NullInteger;
+                }
+                int _index = Null.NullInteger;
+                if (ViewState["_index"] != null)
+                {
+                    _index = int.TryParse(ViewState["_index"].ToString(), out _index) ? _index : Null.NullInteger;
+                }
                 if (lbAddValue.Text == Localization.GetString("SaveButton", LocalResourceFile))
                 {
                     attributeValue = attributeValues.GetSingleRepositoryAttributeValues(_key);