Programs with known issues
Bitdefender
Bitdefender can sometimes block access to Internet Explorer unknowingly to the user. Make sure that Internet Explorer is a trusted application within the program.
More information: https://www.bitdefender.com/support/i-cannot-connect-to-the-internet-865.html?referrer=https%3A%2F%2Fwww.google.com%2F
uBlock Origin
uBlock Origin can cause the add-in to never load in the first place (displays a white screen).
To fix, click the blue "Off" button to whitelist our app domain: