Widget Error

Hi,

I get the following error when I delete a custom control:

!ENTRY com.sap.ip.bi.zen 4 0 2015-06-09 13:15:40.304

!MESSAGE Error message: Unable to get property 'componentDeleted' of undefined or null reference Line Number: 124 Pos: 25 Function: function(b){b.widget.componentDeleted(); a.apply(this,arguments); } URL: http://localhost:59202/aad/zen.res/zen.rt.components.sdk/resources/js/sdk_handler-min.js?version

What can cause such an error?

Thanks.