Customer is getting the message: The terminal server has exceeded the maximum number of allowed connections.

This is from your Microsoft Terminal Server / RDS Server and not from webNetwork. However, some things that you can check. 

You can get this if you are just using RDP to get to a normal windows server. Windows only gives you two connections and those connections may be in use or two disconnected sessions that have not yet timed out. 

The other cause can be that you did run out of terminal server licenses and should check your license server to verify the number of connections you are licensed for and the number that are in use. 

Some commands that might come in handy. 

To get connected to that server remotely : net use /user:username \\\\servername\\share 

To get a list of the sessions: query session /server:servername 

Another command to query user connections: qwinsta /server:servername 

To reset a session : reset session [id] /server:servername 

To logoff your session from remote server: logoff /server:servername