I give you three ways to install Unity 3D on Ubuntu.
- Go to https://forum.unity.com/threads/unity-on-linux-release-notes-and-known-issues.350256/ and download the supported version (to make it executable please run the command chmod +x LinuxEditorInstallerFile).
- Install via Ubuntu Make (sudo apt-add-repository ppa:ubuntu-desktop/ubuntu-make && sudo apt-get update && sudo apt-get install -y ubuntu-make && umake games unity3d && sudo ln -s ~/.local/share/umake/games/unity3d/Unity /usr/local/bin/unity3d)
- Go to https://unity3d.com/unity/qa/patch-releases and download the version for Windows. Then install wine (sudo apt install wine64), download and install .NET 4.5 full, use repair tool if you have an error with netfx_full.mzz (https://support.microsoft.com/en-us/help/2698555/microsoft-net-framework-repair-tool-is-available)
You can resolve the error "Make sure that ntlm_auth >= 3.0.25 is in your path" with the following command:
sudo apt install winbind