Questions[ubuntu-mate](ubuntu)

I've installed mate and xrdp on Ubuntu 18.04. Now I try to connect to this PC from another Ubuntu with Remmina:

I press OK, login window disappears background is same,nothing happens. My ~/.xsession contains mate-session.

xrdp.log contains stuff like this:

[20190818-12:23:09] [DEBUG] Closed socket 17 (AF_UNIX)
[20190818-12:23:12] [DEBUG] Closed socket 17 (AF_UNIX)
[20190818-12:23:15] [DEBUG] xrdp_wm_log_msg: connection problem, giving up
[20190818-12:23:15] [DEBUG] Closed socket 17 (AF_UNIX)
[20190818-12:23:15] [DEBUG] xrdp_wm_log_msg: some problem
[20190818-12:23:15] [DEBUG] xrdp_mm_module_cleanup
[20190818-12:23:15] [DEBUG] Closed socket 16 (AF_INET6 ::1 port 59402)
[20190818-12:24:11] [DEBUG] xrdp_wm_log_msg: connecting to sesman ip 127.0.0.1 port 3350
[20190818-12:24:11] [INFO ] xrdp_wm_log_msg: sesman connect ok
[20190818-12:24:11] [DEBUG] xrdp_wm_log_msg: sending login info to session manager, please wait...
[20190818-12:24:11] [DEBUG] return value from xrdp_mm_connect 0
[20190818-12:24:12] [INFO ] xrdp_wm_log_msg: login successful for display 10
[20190818-12:24:12] [DEBUG] xrdp_wm_log_msg: started connecting
[20190818-12:24:15] [DEBUG] Closed socket 17 (AF_UNIX)
[20190818-12:24:19] [DEBUG] Closed socket 17 (AF_UNIX)
[20190818-12:24:22] [DEBUG] Closed socket 17 (AF_UNIX)
[20190818-12:24:26] [DEBUG] Closed socket 17 (AF_UNIX)
[20190818-12:24:29] [DEBUG] Closed socket 17 (AF_UNIX)
[20190818-12:24:33] [DEBUG] Closed socket 17 (AF_UNIX)
[20190818-12:24:36] [DEBUG] Closed socket 17 (AF_UNIX)

[20190818-12:30:30] [INFO ] calling auth_start_session from pid 6502
[20190818-12:30:30] [DEBUG] Closed socket 7 (AF_INET6 ::1 port 3350)
[20190818-12:30:30] [DEBUG] Closed socket 8 (AF_INET6 ::1 port 3350)
[20190818-12:30:30] [INFO ] /usr/lib/xorg/Xorg :10 -auth .Xauthority -config xrdp/xorg.conf -noreset -nolisten tcp -logfile .xorgxrdp.%s.log  
[20190818-12:30:40] [ERROR] X server for display 10 startup timeout
[20190818-12:30:40] [CORE ] waiting for window manager (pid 6503) to exit
[20190818-12:30:40] [ERROR] X server for display 10 startup timeout
[20190818-12:30:40] [ERROR] another Xserver might already be active on display 10 - see log
[20190818-12:30:40] [DEBUG] aborting connection...
[20190818-12:30:40] [CORE ] window manager (pid 6503) did exit, cleaning up session
[20190818-12:30:40] [INFO ] calling auth_stop_session and auth_end from pid 6502
[20190818-12:30:40] [DEBUG] cleanup_sockets:
[20190818-12:30:40] [DEBUG] cleanup_sockets: deleting /var/run/xrdp/sockdir/xrdp_chansrv_socket_10
[20190818-12:30:40] [DEBUG] cleanup_sockets: deleting /var/run/xrdp/sockdir/xrdpapi_10
[20190818-12:30:40] [DEBUG] cleanup_sockets: failed to delete /var/run/xrdp/sockdir/xrdpapi_10
[20190818-12:30:40] [INFO ] ++ terminated session:  username someuser, display :10.0, session_pid 6502, ip ::ffff:192.115.120.210:44136 - socket: 12

How do I fix or diagnose this brilliant piece of software?

I have a weired sympton with a fresh Windos 10 guest OS under VirtualBox 5.1.28 under Ubutunu-MATE 16.04:

I can't move the window at all, when [x] Auto Capture Keyboard is on.

Neither dragging the outer windows borders (resize), nor the titlebar (indeed just move the virtuabl box. So this is not about auto-resize on or off...). If I deactivate the option, things work fine again. (I do not even understand the relation). – sounds like a virtual box bug? Can't reproduce the opposite, but I have been working with virtual box (and Win7 guests) for long, never encountered this until 2 weeks ago.

But then, common shortcuts I have defined in host and guest, don't work on the guest but rather the host (i.e. WIN-R to get a run programm...). So, of course capturing is desirable.

Just noticed this annoying emoji input ("Emoji Choice") popping up every time I press Ctrl+Shift+E in 18.04. I really need this shortcut to switch to the file explorer in Visual Studio Code but instead I only get the emoji input. Is there a way to disable this or at least change the shortcut? Don't want to change the VCS's shortcut because of this, I'm really used to it

I'm on a clean install of Ubuntu Mate 18.04, the system itself is working with no issues, but I am running dmesg to look at errors and warnings. I like to try to get them all dealt with if possible even if they aren't causing obvious issues right now.

I have an Nvidia card running driver 390.48.

I've got most of the issues dealt with, but one that pops up four times says this:

PKCS#7 signature not signed with a trusted key

Here are +/- three lines in dmesg for context for two of the occurrences (the second one actually captures two):

[    1.157284] ata3: SATA max UDMA/133 abar m2048@0xdf34b000 port 0xdf34b200 irq 126
[    1.157285] ata4: SATA max UDMA/133 abar m2048@0xdf34b000 port 0xdf34b280 irq 126
[    1.157535] e1000e 0000:00:1f.6: Interrupt Throttling Rate (ints/sec) set to dynamic conservative mode
[    1.168128] PKCS#7 signature not signed with a trusted key
[    1.168135] nvidia: loading out-of-tree module taints kernel.
[    1.168138] nvidia: module license 'NVIDIA' taints kernel.
[    1.168138] Disabling lock debugging due to kernel taint

and:

[    1.175479] nvidia-nvlink: Nvlink Core is being initialized, major device number 238
[    1.175681] nvidia 0000:01:00.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=none:owns=io+mem
[    1.175734] NVRM: loading NVIDIA UNIX x86_64 Kernel Module  390.48  Thu Mar 22 00:42:57 PDT 2018 (using threaded interrupts)
[    1.180047] PKCS#7 signature not signed with a trusted key
[    1.181035] nvidia-modeset: Loading NVIDIA Kernel Mode Setting Driver for UNIX platforms  390.48  Wed Mar 21 23:48:34 PDT 2018
[    1.181409] PKCS#7 signature not signed with a trusted key
[    1.181814] [drm] [nvidia-drm] [GPU ID 0x00000100] Loading driver

The line in question is the PKCS line, I understand the driver will "taint" the kernel. From the context it seems like the PKCS warnings are related to the Nvidia driver. Is that expected? This is the driver obtained from the Ubuntu repository, not independently from Nvidia, if that makes a difference. Usually I can look up the Nvidia-specific errors and warnings (which are usually harmless) but this one I didn't find anything.

I have recently installed Ubuntu mate 18.04 on my XPS 15 9560. I cannot adjust the display brightness through any means. I have tried the following:

1. Set the acpi_backlight=vendor in boot parameters
2. used xbacklight, which gives the following results

.

xypnox@xypnox-xps:~$ xbacklight -set 50
No outputs have backlight property

also I followed another question at xbacklight: No outputs have backlight property - No /sys/class/backlight folder, and the output for sudo find /sys/ -type f -iname '*brightness*' is

xypnox@xypnox-xps:~$ sudo find /sys/ -type f -iname '*brightness*'
/sys/devices/platform/dell-laptop/leds/dell::kbd_backlight/brightness_hw_changed
/sys/devices/platform/dell-laptop/leds/dell::kbd_backlight/max_brightness
/sys/devices/platform/dell-laptop/leds/dell::kbd_backlight/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::capslock/max_brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::capslock/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::numlock/max_brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::numlock/brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::scrolllock/max_brightness
/sys/devices/platform/i8042/serio0/input/input4/input4::scrolllock/brightness
/sys/module/video/parameters/brightness_switch_enabled
/sys/module/i915/parameters/invert_brightness