Don’t be long-winded, give the problem and solution directly.

Problems that arise

The solution
Modify /etc/xrdp/sesman.ini

open file /etc/xrdp/sesman.ini

sudo vim /etc/xrdp/sesman.ini

sesman.ini file contents are as follows:

[Globals]
ListenAddress=127.0.0.1
ListenPort=3350
EnableUserWindowManager=1
UserWindowManager=startwm.sh
DefaultWindowManager=startwm.sh

[Security]
AllowRootLogin=1
MaxLoginRetry=4
TerminalServerUsers=tsusers
TerminalServerAdmins=tsadmins

[Sessions]
X11DisplayOffset=10
MaxSessions=10
KillDisconnected=0
IdleTimeLimit=0
DisconnectedTimeLimit=0

[Logging]
LogFile=/var/log/xrdp-sesman.log
LogLevel=DEBUG
EnableSyslog=0
SyslogLevel=DEBUG

[X11rdp]
param1=-bs
param2=-ac
param3=-nolisten
param4=tcp

[Xvnc]
param1=-bs
param2=-ac
param3=-nolisten
param4=tcp
param5=-localhost
param6=-dpi
param7=96

under [Xvnc] param8= -securitytypes and param9=None

[Xvnc]
param1=-bs
param2=-ac
param3=-nolisten
param4=tcp
param5=-localhost
param6=-dpi
param7=96
param8=-SecurityTypes
param9=None

restart XRDP service

sudo service xrdp restart