Hi Rekha,
Fail to add a Primary Key columns for GridGroupingControl might cause this issue. Could you please make this is taken care in your sample. You can add a primary key column by using the below code snippet.
//Adds a primary key column to the TableDescriptor
this.GridGroupingControl1.TableDescriptor.PrimaryKeyColumns.Add("OrderID");
If this is not a case, could you please send me the sample which cause this issue. It will help us to come up with solution. In the meantime, please download our sample and do let us know if you are able to reproduce the issue in our sample.
Forum_56066.zipLet us know if it helps.
Thanks for using Syncfusion products.
Regards,
Gokulkumar.B