Authentication error when providing password in command-line or via GUI

[arekg]

Xpra client on Windows 10, Xpra server on Linux Ubuntu 18.04
Authentication error when providing password in command-line (xpra attach ssh/user:pass@host...) or via GUI (Xpra Launcher -> connect).
When no password privided (xpra attach ssh:user@host.. or blank password field in GUI) connection is possible.
Following error in xpra server log:

2019-06-03 12:01:04,103 Connection lost
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/xpra/server/server_core.py", line 535, in _process_hello
    auth_caps = self.verify_hello(proto, c)
  File "/usr/lib/python2.7/dist-packages/xpra/server/server_core.py", line 625, in verify_hello
    authlog.warn("Warning: client expects a challenge but this connection is unauthenticated")
NameError: global name 'authlog' is not defined
2019-06-03 12:01:14,108 connection timedout: Protocol(SocketConnection(/home/agagalsk/.xpra/TB254-TBHOST-100))

[Antoine Martin]

As per wiki/ReportingBugs, please specify which version you are running at both ends.
This looks like an outdated version on the server at least.

[arekg]

SERVER

 ~ $ xpra --version
xpra v0.15.8
 ~ $ uname -a
Linux HOST 4.10.0-38-generic #42~16.04.1-Ubuntu SMP Tue Oct 10 16:32:20 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
Linux Mint 18.3 Sylvia (GNU/Linux 4.10.0-38-generic x86_64)

CLIENT

c:\Program Files\Xpra>Xpra_cmd.exe --version
xpra v2.5.1-r22424

[Antoine Martin]

Your server version is completely out of date, and full of security issues. Details here: wiki/Packaging/DistributionPackages.

Don't use the packages from Ubuntu, or if you do, report the bugs there (and nothing will happen since they have never applied a single fix in 4 years).

[migration script]

this ticket has been moved to: ​https://github.com/Xpra-org/xpra/issues/2313