Anchor template to find the storage alias:

https://<instance name>.service-now.com/sys_storage_alias_list.do?sysparm_query=table_name%3Dincident_task%5Eelement_name%3Dincident

All this is because there is no real table in the SN database called incident_task - unless the default extension model for task has been modified to Table per class.

And - very important - when moving the database view to "upper" instances, you need to make sure the real name for reference incident (on incident_task) is/remains the same - in my case a_ref_1.