LPD uses TCP protocol and the default port number is 515. You should change the port number if the lpr clients are configured to use other port.
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at webmaster@systemmanager.forsenergy.ru to inform them of the time this error occurred, and the actions you performed just before this error.
More information about this error may be available in the server error log.
Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.