Can't open Unity project: The selected window backend is (null)

Hi, thanks for taking the time to read this. I’m using EndevourOS with i3wm (x11 / nvidia hardware) and am currently trying to open a Unity project, but when I do so using Unity Hub (from unityhub AUR) the project just keeps loading forever…

I have tried launching the editor manually using:

$ ./editors/6000.0.29f1/Editor/Unity -projectPath ./projects/projectname/ -logfile unity.log

This doesn’t work either, but at the end of the unity.log file I get the following error: “The selected window backend is (null)”.

This is my first time posting on this forum, so if I’m missing any important information for this error, feel free to ask :).

Welcome to the forum @sara01 ,
As a total noob I experienced the following:
/tmp
Install Editor needs 10GB at least:

sudo mount -o remount,size=10G /tmp

and then Installs looks like this:


I created an empty project_p1
and then your command line starts the editor with no significant errors in log.
Licensing is another question.
I’m not on Nvidia, and idk whether it matters.
Fun fact that after X11 Cinnamon I swtched to wayland session and it starts there as well.

Just throwing this out there: I’d say I had to replace an AUR package with the Flatpak about 2-3 times. From scanner software to an online translation service to a browser.
Every time I did this I had a stable functioning piece of software. No offense to the AUR–I have many successful AUR apps–but not everything someone did on their own computer is 100% duplicated on someone else’s computer.

you could just try it is all I’m saying --2 cents

I solved the problem. It was something like what you said.

I have two SSDs. When I install the editor on the first one, it doesn’t work. But when I reinstall the editor on the second one (where the root filesystem lives), it works.

I don’t know why. Maybe it has something to do with read/write permissions, or the format of the filesystem…?

Anyway, thanks for the reply, your answer led me to the solution :).

df -h
showed me 7,5G for /tmp in BTRFS, That ‘quota’ wasn’t enough.
Happy editing.