Remmina: Unknown authentication scheme from VNC server: 13, 5, 6, 130, 192

I tried both passwords, adding the line Authentication=VncAuth to the end of .vnc/config.d/vncserver-x11 and disabling encryption

Modifying the .vnc/config.d/vncserver-x11 file changes how vncserver runs in service mode. These settings are ignored if you launch vncserver directly. Given that you're starting vncserver as follows

I have installed vnc in the raspberry and started it with vncserver :1

it means that the authentication method for that vncserver instance will not be using Authentication=VncAuth but instead the default (which Remmina doesn't understand).

To resolve this problem, start vnc server as follows:

$ vncserver -Authentication VncAuth :1

Note that these arguments are case sensitive (and doesn't always give useful error message if you get it wrong).

I know this is an indirect solution for the above error. This will install Real VNC Viewer and use this to create a working VNC connection out of the box.

Download the Real VNC Viewer from here. After installing and starting the program, I had to put the Domain (The raspberry IP and not the "IP-like thing"), the username and the user password.

The installation was done on the command line using:

wget https://www.realvnc.com/download/file/viewer.files/VNC-Viewer-6.20.529-Linux-x64.deb
sudo dpkg -i VNC-Viewer-6.20.529-Linux-x64.deb 

Tested on Ubuntu 18.04.