[X2Go-User] Getting "Access denied for 'password'. Authentication that can continue: publickey, password", used to work

[Chris Green]

I've been running x2go from an xubuntu laptop client to an xubuntu
desktop machine successfully for a year or so.  It has now stopped
working with a pop-up window that says:-

    Access denied for 'password'. Authentication that can continue:
    publickey,password
    Access denied for 'password'. Authentication that can continue:
    publickey,password

(yes, it is repeated like that)

I have moved from xubuntu 18.04 to 19.04 (via 18.10), would this have
caused the problem maybe?  

Whatever, how do I fix this?  The error doesn't make much sense anyway
as it's saying I'm not allowed to use password authentication and then
it's saying I must use either publickey or password.  FWIW I do use
password authentication on my systems, for various reasons public key
doesn't fulfil my requirements.

-- 
Chris Green