WHMCS

We are seeing issues when users update their tickets, i.e. changing the status or the priority and clicking update.

Viewing the ticket list, opening a new ticket, viewing ticket replies and replying to tickets works just fine, but when the user selects a new priority or a new status and clicks "Update" the following error is seen:

Fatal error: Uncaught exception 'kyException' with message 'HTTP error: 405' in /var/www/billing/modules/support/kayako/API/kyRESTClient.php:196
Stack trace:
#0 /var/www/billing/modules/support/kayako/API/kyRESTClient.php(241): kyRESTClient->processRequest('/Tickets/Ticket', 'PUT', Array, Array, Array)
#1 /var/www/billing/modules/support/kayako/API/kyObjectBase.php(269): kyRESTClient->put('/Tickets/Ticket', Array, Array)
#2 /var/www/billing/modules/support/kayako/API/kyObjectWithCustomFieldsBase.php(41): kyObjectBase->update()
#3 /var/www/billing/modules/support/kayako/updateticket.php(26): kyObjectWithCustomFieldsBase->update()
#4 /var/www/billing/modules/support/kayako/viewticket.php(107): require_once('/var/www/billin...')
#5 /var/www/billing/viewticket.php(0): unknown()
#6 {main}
thrown in /var/www/billing/modules/support/kayako/API/kyRESTClient.php on line 196


I've searched both sides and I can't see where the 405 is being generated, can you offer any suggestion or assistance on what might be going wrong here?