If this happens:
Check that the API key has the correct permissions.
Access the query in question and if this takes a while to load it means that it may be timing out and to solve this:
Recreate the query and apply filters to make the results smaller.
Update the API key to have access to the newly created query.
Action the same API call.
If this hasn't worked then raise a new case online and reference the title of this article confirming you have followed the above instructions.