xrdp-sesman: (EE) Couldn't add screen on Fedora 35

[EntityinArray]

Good day, everyone!
Thank you for developing amazing software

I'm trying to set up xrdp, so that I can connect to my home pc remotely.
When logging in, it displays a black screen for a while and then throws this error:

апр 25 10:59:41 fedora xrdp-sesman[2342]: Fatal server error:
апр 25 10:59:41 fedora xrdp-sesman[2342]: (EE) Couldn't add screen
OS: Fedora Linux 35

Full log is:-

апр 25 10:59:41 fedora xrdp[2338]: [INFO ] VNC connecting to 127.0.0.1 5910
апр 25 10:59:41 fedora xrdp-sesman[2339]: pam_unix(xrdp-sesman:session): session opened for user entityinarray(uid=1000) by (uid=0)
апр 25 10:59:41 fedora audit[2339]: USER_START pid=2339 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:unconfined_service_t:s0 msg='op=PAM:session_open grantors=pam_keyinit,pam_limits,pam_systemd,pam_unix acct="entityinarray" exe="/usr/sbin/xrdp-sesman" hostname=? addr=? terminal=:10 res=success'
апр 25 10:59:41 fedora xrdp-sesman[2342]: [INFO ] Starting X server on display 10: Xvnc :10 -auth .Xauthority -geometry 1920x1080 -depth 15 -rfbauth /home/entityinarray/.vnc/sesman_passwd-entityinarray@fedora:10 -bs -nolisten tcp -localhost -dpi 96
апр 25 10:59:41 fedora xrdp-sesman[2342]: Xvnc TigerVNC 1.12.0 - built Feb 15 2022 00:00:00
апр 25 10:59:41 fedora xrdp-sesman[2342]: Copyright (C) 1999-2021 TigerVNC Team and many others (see README.rst)
апр 25 10:59:41 fedora xrdp-sesman[2342]: See https://www.tigervnc.org for information on TigerVNC.
апр 25 10:59:41 fedora xrdp-sesman[2342]: Underlying X server release 12014000, The X.Org Foundation
апр 25 10:59:41 fedora xrdp-sesman[2342]: (EE)
апр 25 10:59:41 fedora xrdp-sesman[2342]: Fatal server error:
апр 25 10:59:41 fedora xrdp-sesman[2342]: (EE) Couldn't add screen
апр 25 10:59:41 fedora xrdp-sesman[2342]: (EE)
апр 25 10:59:44 fedora xrdp[2338]: [ERROR] VNC error 1 after security negotiation
апр 25 10:59:44 fedora xrdp[2338]: [ERROR] VNC error before sending share flag
апр 25 10:59:44 fedora xrdp[2338]: [ERROR] VNC error before receiving server init
апр 25 10:59:44 fedora xrdp[2338]: [ERROR] VNC error before receiving pixel format
апр 25 10:59:44 fedora xrdp[2338]: [ERROR] VNC error before receiving name length
апр 25 10:59:44 fedora xrdp[2338]: [ERROR] VNC error before receiving name
апр 25 10:59:44 fedora xrdp[2338]: [INFO ] VNC error - problem connecting
апр 25 10:59:44 fedora xrdp[2338]: [INFO ] some problem
апр 25 10:59:44 fedora xrdp[2338]: [ERROR] xrdp_wm_log_msg: Error connecting to user session
апр 25 10:59:44 fedora xrdp[2338]: [INFO ] Error connecting to user session
апр 25 10:59:51 fedora xrdp-sesman[2339]: [WARN ] Timed out waiting for X server on display 10 to startup
апр 25 10:59:51 fedora xrdp-sesman[2339]: [INFO ] Session started successfully for user entityinarray on display 10
апр 25 10:59:51 fedora xrdp-sesman[2367]: [INFO ] Starting the xrdp channel server for display 10
апр 25 10:59:51 fedora xrdp-sesman[2339]: [INFO ] Session in progress on display 10, waiting until the window manager (pid 2341) exits to end the session
апр 25 10:59:51 fedora xrdp-sesman[2341]: [WARN ] Timed out waiting for X server on display 10 to startup
апр 25 10:59:51 fedora xrdp-sesman[2341]: [ERROR] There is no X server active on display 10
апр 25 10:59:51 fedora xrdp-sesman[2341]: [ERROR] A fatal error has occured attempting to start the window manager on display 10, aborting connection
апр 25 10:59:51 fedora xrdp-sesman[2339]: [WARN ] Window manager (pid 2341, display 10) exited quickly (0 secs). This could indicate a window manager config problem
апр 25 10:59:51 fedora xrdp-sesman[2339]: [INFO ] Calling auth_stop_session and auth_end from pid 2339
апр 25 10:59:51 fedora xrdp-sesman[2339]: pam_unix(xrdp-sesman:session): session closed for user entityinarray
апр 25 10:59:51 fedora audit[2339]: USER_END pid=2339 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:unconfined_service_t:s0 msg='op=PAM:session_close grantors=pam_keyinit,pam_limits,pam_systemd,pam_unix acct="entityinarray" exe="/usr/sbin/xrdp-sesman" hostname=? addr=? terminal=:10 res=success'
апр 25 10:59:51 fedora audit[2339]: CRED_DISP pid=2339 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:unconfined_service_t:s0 msg='op=PAM:setcred grantors=pam_localuser,pam_unix acct="entityinarray" exe="/usr/sbin/xrdp-sesman" hostname=? addr=? terminal=:10 res=success'
апр 25 10:59:51 fedora xrdp-sesman[2339]: [INFO ] Terminating X server (pid 2342) on display 10
апр 25 10:59:51 fedora xrdp-sesman[2339]: [INFO ] Terminating the xrdp channel server (pid 2367) on display 10
апр 25 10:59:51 fedora xrdp-sesman[2339]: [INFO ] X server on display 10 (pid 2342) returned exit code 1 and signal number 0
апр 25 10:59:51 fedora xrdp-sesman[2367]: Global configuration:
апр 25 10:59:51 fedora xrdp-sesman[2367]:     UseUnixSocket (derived):   true
апр 25 10:59:51 fedora xrdp-sesman[2367]: Security configuration:
апр 25 10:59:51 fedora xrdp-sesman[2367]:     RestrictOutboundClipboard: none
апр 25 10:59:51 fedora xrdp-sesman[2367]:     RestrictInboundClipboard:  none
апр 25 10:59:51 fedora xrdp-sesman[2367]: Chansrv configuration:
апр 25 10:59:51 fedora xrdp-sesman[2367]:     EnableFuseMount            true
апр 25 10:59:51 fedora xrdp-sesman[2367]:     FuseMountName:             thinclient_drives
апр 25 10:59:51 fedora xrdp-sesman[2367]:     FileMask:                  077
апр 25 10:59:51 fedora xrdp-sesman[2367]:     Nautilus 3 Flist Format:   false
апр 25 10:59:51 fedora xrdp-sesman[2367]: chansrv::main: using log file [/home/entityinarray/.local/share/xrdp/xrdp-chansrv.10.log]
апр 25 10:59:51 fedora xrdp-sesman[2339]: [INFO ] xrdp channel server for display 10 (pid 2367) exit code 0 and signal number 0
апр 25 10:59:51 fedora xrdp-sesman[2339]: [INFO ] cleanup_sockets:
апр 25 10:59:51 fedora xrdp-sesman[977]: [INFO ] Process 2339 has exited
апр 25 10:59:51 fedora systemd[1]: session-c2.scope: Deactivated successfully.
░░ Subject: Unit succeeded
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░
░░ The unit session-c2.scope has successfully entered the 'dead' state.
апр 25 10:59:51 fedora xrdp-sesman[977]: [INFO ] ++ terminated session:  username entityinarray, display :10.0, session_pid 2339, ip ::ffff:192.168.2.1:51323 - socket: 12
апр 25 10:59:51 fedora systemd-logind[755]: Session c2 logged out. Waiting for processes to exit.
апр 25 10:59:51 fedora systemd-logind[755]: Removed session c2.

If anyone experienced such problem and knows a solution, I will appreciate any help.
I'm ready to provide any other additional information, if needed.

Thanks!

[matt335672]

@EntityinArray - I've taken the trouble to move your log dump to this issue rather than leaving it in pastebin, where it may disappear.

I think your problem is here:-

Xvnc :10 -auth .Xauthority -geometry 1920x1080 -depth 15 -rfbauth /home/entityinarray/.vnc/sesman_passwd-entityinarray@fedora:10 -bs -nolisten tcp -localhost -dpi 96

I don't think TigerVNC can support this colour depth any more, particularly when it's built with 3D support.

Try setting your client to 24 or 32 bits and see what happens.

[EntityinArray]

Sorry for that, I didn't think this through with pastebin.
Thanks alot, gonna try that out!

[EntityinArray]

Thanks a lot, that works.
Setting color depth on windows RDP client mstsc.exe is a hassle. There is a property in xrdp.ini max_bpp, that allows you to set maximum allowed color depth. Is it possible to limit minimum colordepth (like min_bpp) to prevent mstsc from setting colordepth to 15?

[matt335672]

It isn't currently possible to limit the bpp to a minimum, from my reading of the code, although it could be an interesting one to add. I'll start a discussion on it.

I've never had a problem setting the colour depth on the Windows mstsc.exe client. Am I missing something? It's here in the GUI:-

If you're using an ini file, set the colour depth with something like:-

session bpp:i:24

The default value on my Windows 10 system, if I remove the line entirely, appears to be 32.

[matt335672]

Discussion #2244 started.

[EntityinArray]

Thanks, everything is good now