[Semediawiki-user] Error "Answering the query turned out to be too difficult and was aborted"

[Rob S. <rob...@gm...>]

Very simple queries on our wiki are returning the error "Answering the
query turned out to be too difficult and was aborted. Some results
could be missing. If possible, try using a simpler query instead."

The queries that return the error are of the form {{#ask:[[Part
of::SNOR 06699]]}} where one property is queried on one page. The
search returns only one page (which is correct).

Does anybody know why the error occurs or how to fix the problem?

-r