Hi jas_sl,
We have to add the close button to the TabPrimitives collection of TabControlAdv.
//To add the close button to TabControlAdv
this.tabControlAdv1.TabPrimitivesHost.TabPrimitives.Add(new Syncfusion.Windows.Forms.Tools.TabPrimitive(Syncfusion.Windows.Forms.Tools.TabPrimitiveType.Close, null, System.Drawing.Color.Empty, true, 1, "TabPrimitive0"));
this.tabControlAdv1.TabPrimitivesHost.Visible = true;
Please have a look at the attached sample and let me know if this helps you.
http://websamples.syncfusion.com/samples/tools.Windows/F45097/main.htmBest Regards,
Golda