I've a Ubuntu 20.04 server and installed xrdp, xserver-xorg-core & xorgxrdp in it. Firewall ufw allows 3389/TCP for RDP. However, I get the following error when rdp from Windows 10.

Connection Log
Connection to sesman ip 127.0.0.1 port 3350
Sesman connect ok
Sending login info to session manager, please wait..
Login failed for display 0

Would you kindly suggest solutions?

This ip address is a loopback address. If Win 10 is on another machine, connected across a network, then this address will not work. You need the address of the Ubuntu system that talks to the network.

You can find it with the IP command, or old school ifconfig ethx, where the x is the number of the ethernet card; or iwconfig if its a wireless card.

I can not be more specific, since you didn't supply any information on the network configuration.

I use a computer which runs Windows 10. I ran remote desktop connection in Windows with the specified IP 147.8.191.209 address. This windows computer works fine with Putty to the Ubuntu20.04 server.

"ip a" at the Ubuntu20.04 server, has the following network setup

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether e4:54:e8:53:53:7e brd ff:ff:ff:ff:ff:ff
inet 147.8.191.209/25 brd 147.8.191.255 scope global eno1
valid_lft forever preferred_lft forever
inet6 fe80::e654:e8ff:fe53:537e/64 scope link
valid_lft forever preferred_lft forever

Hopefully, the above information is useful for your reference.

Thank you.

Are you sure you are NOT logged in as the user you are trying to connect with? That will cause the connection to fail.

Here is a link to a reasonable How TO. -->https://linoxide.com/linux-how-to/xr...-from-windows/

Hope this helps.

Red Hat Linux, then much later Fedora & now Ubuntu 20.04 LTS.

Thank you for the suggestion.

I notice that only the account for installing Ubuntu 20.04 server can't get through Windows RDP, the rest linux accounts work fine. Now, the account does not pop the following error msg but returned to Windows RDP.

Connection Log
Connection to sesman ip 127.0.0.1 port 3350
Sesman connect ok
Sending login info to session manager, please wait..
Login failed for display 0

How can I check the account if it's damaged?

If your setup is working on other linux distros, and not on Ubuntu, I think you will have to raise the issue with Ubuntu devs. It might be worth trying it with another Ubuntu install, not necessarily a system set up as a server, just to see if the problem is Ubuntu in general, or specifically this one system; be it hardware or software.

Hello everybody,

In my case, and with much time dispend, I was found a simple resolution when note broke login in register log file xrdp after 50 connection session display

You need to change in both sesmain.in and sesman.ini the field MaxSessions to a greater number than you already have. It seems that some sessions are not set freed in a proper way. Both files are in /etc/xrdp. You would need sudo privileges to edit them.

If things are normal, then it might work - because a different display would have been specified. This kind of error is possibly caused by the DISPLAY environment variable value being overridden by a .profile/.bashrc file. Display 0 is what the first login locally gets - no matter who the login is.