When applying a filter which doesn't have a value (selectbox should be empty), the following error occurs:
Warning: Invalid argument supplied for foreach() in /var/www/html/traq/vendor/traq/controllers/tickets.php on line 661
Warning: Cannot modify header information - headers already sent by (output started at /var/www/html/traq/vendor/traq/controllers/tickets.php:661) in /var/www/html/traq/vendor/avalon/http/request.php on line 176