Connecting to Skype for Business Windows Client
Open Skype for Business 2016 Application and Select the Gear Icon in top right corner:
Select and Enter your username at Sign-In Address and then click Personal and Advanced…
Select Manual Configuration and enter the following for both fields (Internal server name and External server name): sipdir.online.lync.com:443 and Click OK twice.
Click Sign In and you will be prompted with Script Error – Please select Yes to continue
Enter your username and password on the SSO pop up and click Sign in
If you it keeps prompting with the script error, the password or username is incorrect.