Hello：）

I notice that your generated value has an original_{0}，So plz remove that by changing your codes like this following：

<asp:ObjectDataSource ID="ObjectDataSource1" runat="server" DeleteMethod="Delete"
        InsertMethod="Insert" OldValuesParameterFormatString="original_{0}" SelectMethod="GetData"
        TypeName="HealthDiagnosticsTableAdapters.tblPCTTableAdapter" UpdateMethod="Update"
        DataObjectTypeName="System.Guid">
        <UpdateParameters>
            <asp:Parameter Name="id" DbType="Guid" />
            <asp:Parameter Name="pct" Type="String" />
            <asp:Parameter Name="credits" Type="Int16" />
            <asp:Parameter Name="pctUser" Type="String" />
            <asp:Parameter Name="pctPass" Type="String" />
            <asp:Parameter Name="pctCode" Type="String" />
            <asp:Parameter DbType="Guid" Name="Original_id" />
        </UpdateParameters>

…………………………

And then make sure that your UpdateParameter should include all the above parameters with the same correct type in the function。