When creating a new mailbox database, on Exchange 2010, I get the error:
Couldn't mount the database that you specified. Specified database: DBname; Error code: An Active Manager operation failed. Error: The Microsoft Exchange Replication service may not be running on server servername. Specific RPC error message: Error 0x6d9 (There are no more endpoints available from the endpoint mapper) from cli_MountDatabase.
After couple of minutes, it's possible to mount the Database manually.
I experience this everytime a create new mailbox database.
Only sollution, is to uncheck "mount this database", and then manually mount it afterwards ;-)