I upgraded one of my PCs from 22.04.5 to 24.04.1, and it seemed to go smoothly. Using another desktop, still on 22.04.5, though, I cannot connect to it through Remmina client as I normally do (LAN connection, desktop sharing, connecting to the active session, which is my needed condition). I get a black screen with "Connecting to name" a spinning "wheel" in the top left corner of the client window. I have not yet waited it out to see if it ever changes to an error, but it doesn't seem to.
What I've done so far:
- Connected a monitor so I could see what's going on, and I noticed that the new connection defaults call for port 3389, so I changed that in my client (added :3389 to the IP address) and made sure the port was open in UFW on the server and on the client.
- Confirmed that my password doesn't seem to have changed.
- I confirmed that I'm using X11 by running echo $XDG_SESSION_TYPE.
- I even tried changing the protocol on the client side to RDP, which resulted in a different result, "Cannot connect to the ip-address RDP server."
(edited to add a step I forgot).
Lurking in my applications was X11VNC Server, which had the settings I needed to employ to allow me to connect.