You received a voice-related error message in Skype for Business. For help on resolving the issue, contact your support team. For information about troubleshooting voice-related error messages, see Troubleshoot Skype for Business audio issues.
If you received an error message while placing a voice call in Skype for Business, do the following:
Make sure that your Internet connection is online and working properly.
Check the number or contact that you’re trying to reach. Make sure that the number or address is entered correctly.
Send an instant message or email to confirm that the call recipient can receive calls.
Note: Voice calls might get disconnected temporarily if your computer or network is experiencing intermittent connectivity issues.