:~# apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

:~# sudo apt-get install -t stretch-backports xorgxrdp
Reading package lists... Done
Building dependency tree
Reading state information... Done
Recommended packages:
  xorg
The following packages will be upgraded:
  xorgxrdp
1 upgraded, 0 newly installed, 0 to remove and 76 not upgraded.
Need to get 154 kB of archives.
After this operation, 309 kB of additional disk space will be used.
Get:1 http://cdn-fastly.deb.debian.org/debian stretch-backports/main armhf xorgxrdp armhf 1:0.2.8-1~bpo9+1 [154 kB]
Fetched 154 kB in 5s (26.6 kB/s)
(Reading database ... 107197 files and directories currently installed.)
Preparing to unpack .../xorgxrdp_1%3a0.2.8-1~bpo9+1_armhf.deb ...
Unpacking xorgxrdp (1:0.2.8-1~bpo9+1) over (0.9.1-9+deb9u3) ...
Setting up xorgxrdp (1:0.2.8-1~bpo9+1) ...

:~# apt-get update
Hit:1 http://packages.openmediavault.org/public arrakis InRelease
Hit:2 http://security.debian.org stretch/updates InRelease
Hit:3 http://ppa.launchpad.net/ayufan/rock64-ppa/ubuntu xenial InRelease
Get:4 http://deb.ayufan.eu/orgs/ayufan-rock64/releases  InRelease [1339 B]
Hit:5 http://ppa.launchpad.net/webupd8team/java/ubuntu trusty InRelease
Hit:6 https://download.docker.com/linux/debian stretch InRelease
Hit:7 https://dev2day.de/pms stretch InRelease
Hit:8 https://openmediavault.github.io/packages arrakis InRelease
Ign:9 https://dl.bintray.com/openmediavault-plugin-developers/arrakis stretch InRelease
Ign:10 https://dl.bintray.com/openmediavault-plugin-developers/arrakis-docker stretch InRelease
Get:11 https://dl.bintray.com/openmediavault-plugin-developers/arrakis stretch Release [4389 B]
Hit:11 https://dl.bintray.com/openmediavault-plugin-developers/arrakis stretch Release
Get:12 https://dl.bintray.com/openmediavault-plugin-developers/arrakis-docker stretch Release [3540 B]
Hit:12 https://dl.bintray.com/openmediavault-plugin-developers/arrakis-docker stretch Release
Hit:15 http://cdn-fastly.deb.debian.org/debian stretch-backports InRelease
Ign:16 http://cdn-fastly.deb.debian.org/debian stretch InRelease
Hit:17 http://cdn-fastly.deb.debian.org/debian stretch-updates InRelease
Hit:18 http://cdn-fastly.deb.debian.org/debian stretch Release
Fetched 1339 B in 2min 1s (11 B/s)
Reading package lists... Done

:~# apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

:~# dpkg -l | grep xorg
ii  xorgxrdp                                                           1:0.2.8-1~bpo9+1                         armhf        Remote Desktop Protocol (RDP) modules for X.org
ii  xserver-xorg-core                                                  2:1.19.2-1+deb9u5                        armhf        Xorg X server - core server

:~# systemctl status xrdp
● xrdp.service - xrdp daemon
   Loaded: loaded (/lib/systemd/system/xrdp.service; enabled; vendor preset: enabled)
   Active: active (running) since Sun 2019-03-31 13:17:58 CEST; 1 day 21h ago
     Docs: man:xrdp(8)
           man:xrdp.ini(5)
  Process: 1438 ExecStart=/usr/sbin/xrdp $XRDP_OPTIONS (code=exited, status=0/SUCCESS)
  Process: 1414 ExecStartPre=/bin/sh /usr/share/xrdp/socksetup (code=exited, status=0/SUCCESS)
 Main PID: 1462 (xrdp)
    Tasks: 2 (limit: 4915)
   Memory: 6.5M
      CPU: 984ms
   CGroup: /system.slice/xrdp.service
           ├─ 1462 /usr/sbin/xrdp
           └─11997 /usr/sbin/xrdp

Apr 02 10:45:39 RockHomeServer xrdp[9288]: (9288)(-143396336)[ERROR] Cannot read private key file /etc/xrdp/key.pem: Permission denied
Apr 02 10:45:39 RockHomeServer xrdp[9289]: (9289)(-143396336)[ERROR] Cannot read private key file /etc/xrdp/key.pem: Permission denied
Apr 02 10:49:25 RockHomeServer xrdp[10582]: (10582)(-143396336)[ERROR] Cannot read private key file /etc/xrdp/key.pem: Permission denied
Apr 02 10:49:25 RockHomeServer xrdp[10583]: (10583)(-143396336)[ERROR] Cannot read private key file /etc/xrdp/key.pem: Permission denied
Apr 02 10:54:58 RockHomeServer xrdp[11996]: (11996)(-143396336)[ERROR] Cannot read private key file /etc/xrdp/key.pem: Permission denied
Apr 02 10:54:58 RockHomeServer xrdp[11997]: (11997)(-143396336)[ERROR] Cannot read private key file /etc/xrdp/key.pem: Permission denied
Warning: Journal has been rotated since unit was started. Log output is incomplete or unavailable.