This covers any instance where a customer attempts to run a saved report but receives an error message stating "Kintera Query Engine is not available at this time. Please contact customer support."
This is typically caused by poorly constructed query logic or overly complex statements. To resolve it, you can try to re-Create the query from scratch. If that produces the same error, it could be caused by incorrect or incompatible criteria or a system delay, and the query should be recreated through a different type or more comprehensible logic.
For example, you could run an Activities query for event registrants, instead of an Individuals query.