A plugin had an unrecoverable error. Will restart this plugin

Error: Java::ComMicrosoftSqlserverJdbc::SQLServerException: The TCP/IP connection to the host Provider=SQLOLEDB.1, port 1433 has failed. Error: "Provider=SQLOLEDB.1. Verify the connection properties. Make sure that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port. Make sure that TCP connections to the port are not blocked by a firewall.".
Exception: Sequel::DatabaseConnectionError