When the dispose method is called, the static INSTANCE property is set to null, which means there is no query handler (neither the original nor the custom handler).
So I've added a control to call the default handler if the INSTANCE property is set to null
When the dispose method is called, the static INSTANCE property is set to null, which means there is no query handler (neither the original nor the custom handler). So I've added a control to call the default handler if the INSTANCE property is set to null
Fix #1195