Hi Pat,
The DrillUpDownClick event can't be removed whereas to restrict the expansion in OLAP Chart kindly follow the below code snippet:
this.olapChart1.OlapDataManager.CurrentReport.ShowExpanders = false;
this.olapChart1.DataBind();
Here is an online sample link exactly demonstrating your requirement to restrict the expansion in OLAP Chart control:
http://bi.syncfusion.com/8.4.0.10/BI/Web/OlapChart/Samples/3.5/Chart%20Appearance/Expanders%20Visibility%20Demo/CS/ExpandersVisibilityDemo.aspx?args=1NOTE: If you want to remove or turn off the DrillUpDownClick event then kindly open an incident so that we can provide you the fix through patch.
Thanks,
E.Hari Venkatesh.