sudo apt update && sudo apt -y upgrade
sudo apt-get purge xrdp
sudo apt install -y xrdp
sudo apt install -y xfce4
sudo apt install -y xfce4-goodies
sudo cp /etc/xrdp/xrdp.ini /etc/xrdp/xrdp.ini.bak
sudo sed -i ‘s/3389/3390/g’ /etc/xrdp/xrdp.ini
sudo sed -i ‘s/max_bpp=32/#max_bpp=32\nmax_bpp=128/g’ /etc/xrdp/xrdp.ini
sudo sed -i ‘s/xserverbpp=24/#xserverbpp=24\nxserverbpp=128/g’ /etc/xrdp/xrdp.ini
echo xfce4-session > ~/.xsession

sudo nano /etc/xrdp/startwm.sh
edit these lines to:
# test -x /etc/X11/Xsession && exec /etc/X11/Xsession
# exec /bin/sh /etc/X11/Xsession

add these lines:
# xfce
startxfce4

sudo /etc/init.d/xrdp start