647: Unable to connect to the Licence Server and all licences are being used up by the same computer

Symptoms:

A client or clients can't find the Licence Server and the Licence Server's log suggests the same client is using up all the available licences.

The reason behind this is that the client machine starts up, sends an 'alive' message to the Licence Server, which assigns it ID 1 and tells the client that it's OK to start up. That message doesn't get back to the client so the client then sends another 'alive' message. The Licence Server gets this and thinks it's a new client starting up so then assigns it ID 2 and tells the client that it's OK to start up. That message doesn't get back to the client so the client then sends another 'alive' message... and so on... This results in the client machine never being able to start Sibelius and the Licence Server using up all the available licences.

The main cause for this is the message from the Licence Server is being blocked by firewall rules or filtering on one of the switches between the server and the client.

Solutions:

There are three things you can do to help:

• Tell the Licence Server not to assign a different client ID when the same client tries to reconnect:
  
  On the server, open the Licence Server Control Panel and go to the Server Options tab. On the right hand side, tick the Assign same client ID to reconnecting clients.
• Check to see if the server where the Licence Server is installed has more than one network card. If you have two network cards, try disabling one and try running Sibelius on the client again. If it's absolutely necessary that you need two network cards in the server (which is not recommended anyway) then you will need to find another server to run the Sibelius Licence Server.
• Check all firewalls and network filtering between the server and the client machine. To help, you may want to use a network sniffer, such as WireShark. This will allow you to see if the network packets sent from the server are reaching the client machine.