Note: this issue relates only to users who are using Bentley Managed Services. Connecting to MAS environment authentication failure screen is received after entering credentials in WIndows Security window.
This happens when incorrect credentials are passed to server.
Make sure correct password is entered. If password is received by email please do enter password in WIndows Security window by typing it instead of using copy/paste from email application. Copy/Paste from mail sometimes fails, as word dividers are copied to password field.