How to fix the agent widget error "login.microsoftonline.com refused to connect"

After installing Live Assist for Dynamics 365 (LAD365), some users might not be able to load the agent widget. They may encounter an error that states "login.microsoftonline.com refused to connect."

There are two ways to fix this issue:

• Set up Multi-Factor Authentication (MFA) (recommended)
• Disable Multi-Factor Authentication (MFA) for the entire organization (not recommended except for trial or test accounts)

Option 1: Set up Multi-Factor Authentication (MFA) 

Note: The steps below must be done by the agent that is having the error. 

1. Sign in to the Microsoft Dynamics 365 instance where LAD365 is installed. Enter your e-mail address and then password as you normally do and then click Sign in.
2. After you sign in, you will be prompted for more information. Click Next. Follow the instructions that appear on screen to set up your account for MFA. If you need help, consult this article on the Microsoft support site. 
3. Use the Microsoft Authenticator app or your chosen MFA method each time you sign in to the Dynamics 365 instance. 

After you start logging in using MFA, the agent widget should load properly as shown below.

Option 2: Disable Multi-Factor Authentication (MFA) for the Whole Organization (not recommended for production accounts)

Note: If this option is chosen, the steps below must be done by the system administrator. They cannot be done by individual users. 

It is also possible to disable Multi-Factor Authentication at a whole organization level. We do not recommend this approach, except in the case of trial accounts. Please be careful as this reduces the security of accounts. If you choose to follow this option, you do so at your own risk.

1. Sign in to the Microsoft Entra admin center with the admin account for your organization. 
2. Follow the steps in this Microsoft article to find the security defaults setting and set it to Disabled (not recommended). Review the conditional security policies to confirm that MFA is not required. 

Once the MFA has been turned off, the agent widget will load properly on your next log-in.