If you want to add a new resource to RadScheduler you will have to rebind it that is why we do not recommend performing such functionality from inside the advanced form.
If you want achieve such functionality we recommend using custom attributes instead as it is explained in thse KBs-Related Load on Demand RadComboBoxes in the advanced form of RadScheduler and Implement related RadComboBox controls in the advanced form.
Hope this will be helpful.
the Telerik team
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