Page cannot be loaded error when Create/Update ticket

I am new to this RT,

I am facing problem when I am creating/Updating the ticket.
Issue :
After entering details in the required fields, When I click the
Create/Update Ticket. I am getting “Page cannot be loaded” error message.
If I refresh the page and entering the details again, I am able to save
the changes.

Please help me resolve this.

Regards,
Parani