When the EMVO Gateway cannot reach the Hub, the session token refresh mechanism doesn't work. This makes the EMVO Gateway fire off a warning email to the SPOC with the message you received - "Session Key Failure". We advise OBPs to request a new Session Token for the affected environment and update it every time you receive this response/information from EMVO Gateway.
To verify if the Session Token has been correctly refreshed, we recommend performing a Product Pack Verification.
If you receive a Distribution callback, then the Session Token has been successfully refreshed.