The T is e-mailing companies with large numbers of employees who have commuter-rail zone passes today. One of those workers forwards this copy of the e-mail:
Dear MBTA Commuter Rail Zone Pass or Charlie Ticket Holder,
There is a problem with the encoding of some September monthly passes on Commuter Rail and CharlieTickets. This does not affect the CharlieCard/Link pass for the bus and subway.
What happened and to how many tickets?