My XRDP suddenly does not work. What should I check?

[Magicloud]

I am on NixOS 25.5 with everything frequently upgraded. My XRDP setup worked quite well until the end of last month. I did not use it for a few days, today, when I connected, I got "Error connecting to Xorg".

The "Connection Log" showed in RDP window after login is:

connecting to sesman on sesman.socket
sesman connect ok.
Performing login request for magicloud
sending login info to sesion manager, please wait...
login was successful - creating session
sending create session request to session manager. Please wait...
session is available on display 11 for user magicloud
Connecting to session
started connecting
Error connecting to Xorg - check log
Error connecting to user session

ps showed that Xorg and desktop apps are running.

Xrdp-sesman log shows:

Jun 05 16:23:26 nixos xrdp-sesman[16377]: [INFO ] starting xrdp-sesman with pid 16377
Jun 05 16:23:26 nixos xrdp-sesman[16377]: [INFO ] Sesman now listening on /var/run/xrdp/sesman.socket
Jun 05 16:23:34 nixos xrdp-sesman[16377]: [INFO ] Socket 13: connection accepted from AF_UNIX
Jun 05 16:23:34 nixos xrdp-sesman[16377]: [INFO ] Received system login request from xrdp for user: magicloud IP: ::ffff:192.168.0.114
Jun 05 16:23:34 nixos xrdp-sesexec[16440]: [INFO ] starting xrdp-sesexec with pid 16440
Jun 05 16:23:34 nixos xrdp-sesexec[16440]: [INFO ] TerminalServerUsers group tsusers doesn't exist. Access granted for magicloud
Jun 05 16:23:34 nixos xrdp-sesexec[16440]: [INFO ] Access permitted for user: magicloud
Jun 05 16:23:34 nixos xrdp-sesman[16377]: [INFO ] Received sys login status for magicloud : logged in
Jun 05 16:23:34 nixos xrdp-sesman[16377]: [INFO ] Received request from xrdp to create a session for user magicloud
Jun 05 16:23:34 nixos xrdp-sesman[16377]: [INFO ] Found X server running at /tmp/.X11-unix/X10
Jun 05 16:23:34 nixos xrdp-sesexec[16440]: pam_unix(xrdp-sesman:session): session opened for user magicloud(uid=1000) by (uid=0)
Jun 05 16:26:35 nixos xrdp-sesman[16377]: [INFO ] Socket 13: connection accepted from AF_UNIX
Jun 05 16:26:35 nixos xrdp-sesman[16377]: [INFO ] Received system login request from xrdp for user: magicloud IP: ::ffff:192.168.0.114
Jun 05 16:26:35 nixos xrdp-sesexec[17077]: [INFO ] starting xrdp-sesexec with pid 17077
Jun 05 16:26:36 nixos xrdp-sesexec[17077]: [INFO ] TerminalServerUsers group tsusers doesn't exist. Access granted for magicloud
Jun 05 16:26:36 nixos xrdp-sesexec[17077]: [INFO ] Access permitted for user: magicloud
Jun 05 16:26:36 nixos xrdp-sesman[16377]: [INFO ] Received sys login status for magicloud : logged in
Jun 05 16:26:36 nixos xrdp-sesman[16377]: [INFO ] Received request from xrdp to create a session for user magicloud
Jun 05 16:26:36 nixos xrdp-sesman[16377]: [INFO ] ++ reconnected session: username magicloud, display :11.0, session_pid 16440, ip ::ffff:192.168.0.114
Jun 05 16:26:36 nixos xrdp-sesexec[17077]: [INFO ] xrdp-sesexec pid 17077 is now logging out

XRDP log shows:

[2025-06-05T16:23:26.509+0800] [INFO ] starting xrdp-sesman with pid 16377
[2025-06-05T16:23:26.563+0800] [INFO ] Sesman now listening on /var/run/xrdp/sesman.socket
[2025-06-05T16:23:34.577+0800] [INFO ] Socket 13: connection accepted from AF_UNIX
[2025-06-05T16:23:34.584+0800] [INFO ] Received system login request from xrdp for user: magicloud IP: ::ffff:192.168.0.114
[2025-06-05T16:23:34.591+0800] [DEBUG] Calling exec (excutable: /nix/store/ir1k6g953p730hfi6g8cdll3nfc5g20s-xrdp-0.10.3/libexec/xrdp/xrdp-sesexec, arguments: xrdp-sesexec -c /nix/store/gaji6argwydcprcbxb81jrvwb3jw0hlr-xrdp.conf/sesman.ini)
[2025-06-05T16:23:34.591+0800] [DEBUG] Closed socket 13 (AF_UNIX)
[2025-06-05T16:23:34.602+0800] [INFO ] starting xrdp-sesexec with pid 16440
[2025-06-05T16:23:34.796+0800] [INFO ] TerminalServerUsers group tsusers doesn't exist. Access granted for magicloud
[2025-06-05T16:23:34.802+0800] [INFO ] Access permitted for user: magicloud
[2025-06-05T16:23:34.809+0800] [DEBUG] Closed socket 9 (AF_UNIX)
[2025-06-05T16:23:34.809+0800] [INFO ] Received sys login status for magicloud : logged in
[2025-06-05T16:23:34.821+0800] [INFO ] Received request from xrdp to create a session for user magicloud
[2025-06-05T16:23:34.827+0800] [DEBUG] session_list_get_bydata: search policy=UB type=Xorg U=1000 B=24 D=(2560x1080) I=::ffff:192.168.0.114
[2025-06-05T16:23:34.834+0800] [DEBUG] session_list_get_bydata: No matches found
[2025-06-05T16:23:34.840+0800] [INFO ] Found X server running at /tmp/.X11-unix/X10
[2025-06-05T16:23:34.846+0800] [DEBUG] Did not find a running X server at /tmp/.X11-unix/X11
[2025-06-05T16:23:34.853+0800] [DEBUG] Did not find a running X server at /tmp/.X11-lock
[2025-06-05T16:23:34.860+0800] [DEBUG] Closed socket 15 ([::]:5911)
[2025-06-05T16:23:34.866+0800] [DEBUG] Did not find a running X server at 5911
[2025-06-05T16:23:34.872+0800] [DEBUG] Closed socket 15 ([::]:6011)
[2025-06-05T16:23:34.878+0800] [DEBUG] Did not find a running X server at 6011
[2025-06-05T16:23:34.884+0800] [DEBUG] Closed socket 15 ([::]:6211)
[2025-06-05T16:23:34.890+0800] [DEBUG] Closed socket 13 (AF_UNIX)
[2025-06-05T16:23:34.947+0800] [DEBUG] Waiting for X server to start on display :11
[2025-06-05T16:23:34.947+0800] [DEBUG] Calling exec (excutable: /nix/store/ir1k6g953p730hfi6g8cdll3nfc5g20s-xrdp-0.10.3/libexec/xrdp/waitforx, arguments: /nix/store/ir1k6g953p730hfi6g8cdll3nfc5g20s-xrdp-0.10.3/libexec/xrdp/waitforx -d :11)
[2025-06-05T16:23:34.956+0800] [INFO ] Starting X server on display 11: /nix/store/pl2mapfil2bi7bdsypqyi6xa7b7asmjm-xorg-server-21.1.16/bin/Xorg :11 -auth .Xauthority -modulepath /nix/store/kbhc8rif9r3fi2ycni1plmdvgqxvgk81-xorgxrdp-0.10.4/lib/xorg/modules,/nix/store/pl2mapfil2bi7bdsypqyi6xa7b7asmjm-xorg-server-21.1.16/lib/xorg/modules -config /nix/store/kbhc8rif9r3fi2ycni1plmdvgqxvgk81-xorgxrdp-0.10.4/etc/X11/xrdp/xorg.conf -noreset -nolisten tcp -logfile .xorgxrdp.%s.log
[2025-06-05T16:23:34.963+0800] [DEBUG] waitforx: Opening display :11. Attempt 1 of 10
[2025-06-05T16:23:34.965+0800] [DEBUG] Calling exec (excutable: /nix/store/pl2mapfil2bi7bdsypqyi6xa7b7asmjm-xorg-server-21.1.16/bin/Xorg, arguments: /nix/store/pl2mapfil2bi7bdsypqyi6xa7b7asmjm-xorg-server-21.1.16/bin/Xorg :11 -auth .Xauthority -modulepath /nix/store/kbhc8rif9r3fi2ycni1plmdvgqxvgk81-xorgxrdp-0.10.4/lib/xorg/modules,/nix/store/pl2mapfil2bi7bdsypqyi6xa7b7asmjm-xorg-server-21.1.16/lib/xorg/modules -config /nix/store/kbhc8rif9r3fi2ycni1plmdvgqxvgk81-xorgxrdp-0.10.4/etc/X11/xrdp/xorg.conf -noreset -nolisten tcp -logfile .xorgxrdp.%s.log)
[2025-06-05T16:23:35.965+0800] [DEBUG] waitforx: Opening display :11. Attempt 2 of 10
[2025-06-05T16:23:35.972+0800] [DEBUG] waitforx: Opened display :11
[2025-06-05T16:23:35.977+0800] [DEBUG] waitforx: Waiting for outputs. Attempt 1 of 10
[2025-06-05T16:23:35.983+0800] [DEBUG] waitforx: Display :11 ready with 1 RandR outputs
[2025-06-05T16:23:35.989+0800] [DEBUG] waiting for pid 16445 to exit
[2025-06-05T16:23:35.994+0800] [INFO ] X server :11 is working
[2025-06-05T16:23:36.609+0800] [INFO ] Starting window manager for display :11
[2025-06-05T16:23:36.841+0800] [DEBUG] adding login info for utmp: 16450 - 11 - magicloud - ::ffff:192.168.0.114
[2025-06-05T16:23:36.924+0800] [DEBUG] The user session on display 11 did not request a specific window manager
[2025-06-05T16:23:36.199+0800] [DEBUG] The user home directory window manager configuration is enabled but window manager program does not exist: /home/magicloud//nix/store/gaji6argwydcprcbxb81jrvwb3jw0hlr-xrdp.conf/startwm.sh
[2025-06-05T16:23:36.142+0800] [INFO ] Starting the xrdp channel server for display :11
[2025-06-05T16:23:36.258+0800] [INFO ] Using the default window manager on display 11: /nix/store/gaji6argwydcprcbxb81jrvwb3jw0hlr-xrdp.conf/startwm.sh
[2025-06-05T16:23:36.331+0800] [INFO ] Session in progress on display :11. Waiting until the window manager (pid 16450) exits to end the session
[2025-06-05T16:23:36.337+0800] [DEBUG] Calling exec (excutable: /nix/store/ir1k6g953p730hfi6g8cdll3nfc5g20s-xrdp-0.10.3/sbin/xrdp-chansrv, arguments: /nix/store/ir1k6g953p730hfi6g8cdll3nfc5g20s-xrdp-0.10.3/sbin/xrdp-chansrv)
[2025-06-05T16:23:36.390+0800] [DEBUG] Calling exec (executable: /nix/store/gaji6argwydcprcbxb81jrvwb3jw0hlr-xrdp.conf/startwm.sh, arguments: /nix/store/gaji6argwydcprcbxb81jrvwb3jw0hlr-xrdp.conf/startwm.sh )
[2025-06-05T16:23:36.454+0800] [DEBUG] Closed socket 9 (AF_UNIX)

[matt335672]

Duplicate of #3539