[winswitch] xpra v4.3-r40 initialization error: cannot find any live servers to connect to

[yonatan zaken]

Hi All,
Just installed the latest release.

When running the following:
xpra start --start=firefox; sleep 3; xpra attach

This is the terminal output:
==================================================
Entering daemon mode; any further errors will be reported to:
  /run/user/1000/xpra/S20128.log
2021-05-25 22:28:25,422 Warning: zlib is the only compressor enabled
2021-05-25 22:28:25,422  install and enable lz4 support for better
performance
2021-05-25 22:28:25,422 Warning: 'rencode' packet encoder not found
2021-05-25 22:28:25,422  the other packet encoders are much slower
2021-05-25 22:28:25,422 Xpra GTK3 X11 client version 4.3-r40 64-bit
2021-05-25 22:28:25,518  running on Linux Ubuntu 18.04 bionic
2021-05-25 22:28:25,519  window manager is 'GNOME Shell'
2021-05-25 22:28:25,958 GStreamer version 1.14.5 for Python 3.6.9 64-bit
2021-05-25 22:28:26,035 created unix domain socket
'/run/user/1000/xpra/clients/y10-20137'
2021-05-25 22:28:26,099 removing unix domain socket
'/run/user/1000/xpra/clients/y10-20137'
xpra initialization error:
 cannot find any live servers to connect to
==================================================

And this is the log context:
==================================================
failure on /tmp/.X11-unix/X19890: [Errno 2] No such file or directory:
'/tmp/.X11-unix/X19890'
2021-05-25 22:25:26,531 cannot access python uinput module:^[[0m
2021-05-25 22:25:26,531  No module named 'uinput'^[[0m
xpra initialization error:
failed to execute xvfb command ['Xvfb-for-Xpra-S19890', '+extension',
'GLX', '+extension', 'Composite', '-screen', '0', '8192x4096x24+32',
'-nolisten', 'tcp', '-noreset', '-auth'    ,
'/run/user/1000/gdm/Xauthority', '-dpi', '96', '-displayfd', '6']: [Errno
2] No such file or directory: 'Xvfb': 'Xvfb'
==================================================

Any idea how to solve this matter?

*Cheers,*
*Yonatan*