Description:
This message indicates that too many connections are trying to use the same resources. For example, if only 10 simultaneous Zaptel connections are allowed, the connection number 11 will fail and send this message.

Solution:

• Login to the system administration
• Navigate to 'System: Servers'
• Click on the 'Edit' button
• Change the Channel group of options, set 'Zaptel'='255' for example
• Click on the 'Save' button
• Click on the 'Restart' button