Catchable fatal error: Object of class SMWQueryResult could not be converted to string in /path/to/extensions/SemanticMediaWiki/includes/SMW_QueryProcessor.php on line 319

This error is caused when using format=count in an #ask query, and takes down the article page. Hopefully this is enough to reproduce the bug. If not, I can probably do more testing. The query looks like this:

{{#ask:[[Category:Some category]][[Some property::{{PAGENAME}}]]|format=count}}

Version: unspecified
Severity: critical