What Does a “Calls will no longer be automatically placed due to errors” warning mean?

MassTransit can be configured to place automatic calls to Contacts and to also retry these automatic calls when errors (such as connection, or transfer failures) are encountered.

These settings are on the Outgoing Calls tab for the Contact.

When the maximum number of connection attempts have been made MassTransit will no longer place automatic calls for the Contact and will log this warning.  You will need to make a successful manual connection to reset the automatic calls.