When using the Web Launch for RPAS, the user logon is invalid

We have deployed the web launch capability for RPAS, so we are using the classic client with web launch.  We are on V14.1.

When the user logs on, they have the option for username/password and then domain.  Once they enter this, the classic client is launched.  When the classic client is launched, a window pops up and says the username/password is incorrect.  This is not the case, the username and password entered was correct, and we just enter it again and the logon is valid.

This happens every time with all users, so this is not a case of entering invalid username/password.