Are you able to provide the transaction UUID for us to check ?
This is a secure acceptance error ,so we need the error code to identify what is wrong.
Meanwhile, may I know if you are still facing this error now?
We are also investigating a reported issue which could be related , where "Initially Merchants and internal users were complaining that after logging into PROD EBC they would see “HTTP Error 502 - Bad Gateway” or “This Page can’t be displayed” error when doing a transaction search.
This eventually lead to Merchants and internal users being unable to log into the EBC receiving the message
“The Business Center is unavailable at the moment. Please try again later.”