Due to security requirements, the system logs out users who have been inactive for fifteen minutes, or who have a concurrent login to their account. The 403 message and error page you have encountered are the errors encountered if your instance of TenderBoard has been logged out. The system prompts you after an hour that it will log you out shortly, but if you are on a separate tab (or your device is in sleep mode), the message can be missed.
If you were completing a form, save it to drafts, then refresh your page or close the tab and re-open it to continue where you left off.
For further assistance, please email in to us at support@tenderboard.biz and include the reference number and description of the deal you are trying to submit for, so that we will be able to expedite on your support request quicker.