I've never seen it, I'm getting the errors via email.

There was another today, same search. 

Query:
SELECT * FROM `sys_profiles` INNER JOIN `bx_groups_data` ON `bx_groups_data`.`id`=`sys_profiles`.`content_id` INNER JOIN `sys_accounts` ON `sys_accounts`.`id`=`sys_profiles`.`account_id` INNER JOIN `bx_groups_meta_locations` ON `bx_groups_meta_locations`.`object_id`=`bx_groups_data`.`id`WHERE 1 AND `sys_profiles`.`status` ='active' AND `sys_profiles`.`type` ='bx_groups' AND `bx_groups_data`.`allow_view_to` IN(3,5,'c',5) AND `bx_groups_meta_locations`.`country` ='PL' AND `bx_groups_meta_locations`.`state` ='śląskie' LIMIT 0, 4

Mysql error:
Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8mb4_unicode_ci,COERCIBLE) for operation '='

Location:
The error was found in getAll function in the file /home/manofteal/public_html/inc/classes/BxDolSearch.php at line 764.

Called script:
/searchKeyword.php

Request parameters:

array (  'type' => 'location_country_state',  'keyword' => 'PL',  'state' => 'śląskie',  'lang' => 'en', )