It seems it's not possible to sort event participants by name after the search. To reproduce:
- Go to events, find participants,
- Select an event under event name,
- Select participant status (example registered),
- Hit the search button.
- The expected results are displayed,
- now click on the Participant column of the search results to sort alphabetically by name
- now you get 'No matches found' for our search criteria.
- Hit the search button again.
Now the results are redisplayed with this warning message:
Warning: array_key_exists(): The first argument should be either a string or an integer in CRM_Utils_Array::value() (line 55 of /srv/buildkit/build/d46/sites/all/modules/civicrm/CRM/Utils/Array.php). Notice: Array to string conversion in CRM_Contact_BAO_Query::buildQillForFieldValue() (line 5753 of /srv/buildkit/build/d46/sites/all/modules/civicrm/CRM/Contact/BAO/Query.php).
The version of CiviCRM Version is 4.6.24.
It seems this un-expected behaviour only happens when searching for events participants and Participant status is selected.