RDP Relay session does not start from MyAccess page: TypeError

RDP Relay links don't work in the User Console (MyAccess)
An error or popup browser dialog box reports a TypeError
Failed to launch RDP Relay link from MyAccess using browsers other than Internet Explorer:

• Mozilla Firefox reports:
  TypeError: MsRdpClient.AdvancedSettings2 is undefined
  
  
• Microsoft Edge reports:
  TypeError: Unable to set property 'RDPPort' of undefined or null reference
  
  
• Google Chrome reports:
  TypeError: Cannot set property 'RDPPort' of undefined
  
  

At the time of writing this document, RDP Relay works only on Internet Explorer.

Launching RDP Relay links from an unsupported browser (other than IE).

For more details, please refer to:

• The NOTE section of Starting a Remote Desktop Session by Using an RDP Relay
  
• Troubleshooting: The RDP Relay Session Does Not Start From the myaccess Page.