Error when i try view my tickets

Hi.

When i try to view my tickets, don't display anything, no entries and no error messages, but when i see my error log i have this:

2015-05-25 11:32:04 ***** ERROR ***** Exception-[42725] SQLSTATE[42725]: Ambiguous function: 7 ERROR: function concat(character varying, unknown) is not unique
LINE 1: ...ype", ticket.name as "name", coalesce(T3.fullName,concat(T3....
^
HINT: Could not choose a best candidate function. You might need to add explicit type casts.
2015-05-25 11:32:04 ***** ERROR ***** For query : select ticket.id as "id", T1.name as "nameProject", T2.name as "nameTicketType", ticket.name as "name", coalesce(T3.fullName,concat(T3.name,' #')) as "nameUser", T4.sortOrder || '#split#' ||T4.name || '#split#' ||COALESCE(T4.color,'') as "colorNameUrgency", T5.sortOrder || '#split#' ||T5.name || '#split#' ||COALESCE(T5.color,'') as "colorNamePriority", T6.sortOrder || '#split#' ||T6.name || '#split#' ||COALESCE(T6.color,'') as "colorNameStatus", ticket.actualDueDateTime as "actualDueDateTime", T7.name as "nameProduct", T8.name as "nameTargetVersion", T9.fullName as "nameResource", ticket.handled as "handled", ticket.done as "done", ticket.idle as "idle" from ticket left join project as T1 on ticket.idProject = T1.id left join type as T2 on ticket.idTicketType = T2.id left join resource as T3 on ticket.idUser = T3.id left join urgency as T4 on ticket.idUrgency = T4.id left join priority as T5 on ticket.idPriority = T5.id left join status as T6 on ticket.idStatus = T6.id left join product as T7 on ticket.idProduct = T7.id left join version as T8 on ticket.idVersion = T8.id left join resource as T9 on ticket.idResource = T9.id where ticket.idle=0 and ticket.idProject in (0, 20) and ( (1=1) ) order by ticket.id desc
2015-05-25 11:32:04 ***** ERROR ***** Strack trace :
2015-05-25 11:32:04 ***** ERROR ***** #0 Sql->query called at [/opt/projeqtor/tool/jsonQuery.php:459]