When using GridTemplateColumn, the SortExpression value should match the field a control in the template is bound to:
<telerik:GridTemplateColumn
UniqueName="TemplateColumn"
HeaderText="Template Column"
SortExpression="City">
<ItemTemplate>
<%# Eval("City") %>
</ItemTemplate>
</telerik:GridTemplateColumn>
Regards,
Pavlina
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items