Unless I'm missing something, this is NOT available in the stated release. It is mentioned in the release notes that it's corrected, however no references to id exist in any "throw new ArgumentOutOfRangeException(...)" in RadComboBox.cs, version 2014.3.1209 The only thing that appears to reference the control ID is the indexed access of the RadComboBoxItemCollection.
Hello, I am glad to inform you that this feature is already added to the Telerik UI for ASP.NET AJAX suit and will be available in Q3 2014 SP1 release. Regards, Aneliya Petkova
This request is now 4 months old. It involves one line of code. What does "approved" mean for these requests? Having a feedback portal doesn't mean anything if you don't actually ACT on the feedback. Note that the Microsoft dropdownList control provides this error message which is significantly better than the RadComboBox message "[ArgumentOutOfRangeException: 'ddlCountry' has a SelectedValue which is invalid because it does not exist in the list of items."
Just change line 1635 to this: throw new ArgumentOutOfRangeException("value", this.ID + " Selection out of range: " + cachedSelectedValue);