Avalonia not showing on the last version of Linux Mint

[lncproducciones]

Describe the bug

After my last Linux update, Avalonia projects doesn't work anymore. I mean, even the project builds and starts, no MainWindow is shown.

Please help!

To Reproduce

On Linux Mint 22.3, without any changes:

1. dotnet new avalonia.app -o MiProyecto
2. cd MiProyecto
3. dotnet run

Expected behavior

The form must to be shown.

Avalonia version

12.1.3

OS

Linux

Additional context

No response

[timunie]

At the moment there isn't much we can do. My guess it could be a driver issue.

If you run a dotnet console app it will perfectly run, right?

I have also a Mint installation. If you upload your sample I can double check if I face the same issue.

[lncproducciones]

Sure, I'm attaching my sample project, and the video with the step-by-step to reproduce it. Please, help!

Answering your question, All my console, WebApi and Razor projects are working properly, only failing the Avalonia projects.

MySampleProject.zip

[timunie]

hmm I am also using Mint with the latest versions installed. Also the cinnamon desktop (btw: What theme is it? The lnc one?)

Here is my output:

I wonder if it may be a driver issue or something.

[timunie]

I asked AI which drivers should be installed. It gave me a few things to test:

1. Missing .NET runtime or wrong version

The app may require a specific .NET version (e.g., .NET 8) that isn't installed. Run:

dotnet --version

Your project uses NET10.

2. Missing graphics libraries

Avalonia on Linux needs certain system libraries for rendering. The most common missing ones are:

• libgtk-3 / libX11 — for window management
• libgl1 / libglx — for OpenGL
• libasound2 — for audio (if used)

Install them with:

sudo apt install libgtk-3-0 libx11-6 libgl1 libglx-mesa0 libasound2

3. Wayland vs X11 display server

Linux Mint can run on either X11 or Wayland. Avalonia's Linux backend works best on X11. If the other person is on Wayland, try:

export DISPLAY=:0
dotnet run

Or log in using the X11 session from the login screen.

4. Different desktop environment or GPU drivers

Some GPU drivers (especially NVIDIA) may not be properly configured. Check:

glxinfo | grep "OpenGL renderer"

[lncproducciones]

Thank you very much for your reply. Regarding the Linux Mint setup, I created it to customize the computers for my software venture (LNC Producciones).

As for the issue I reported, I was surprised that it worked for you, so I continued investigating on my own.

I found and fixed the cause. It wasn't the graphics driver: Intel HD Graphics 520 (i915), Xorg/DRI, and Iris/Mesa were all working correctly, with no kernel GPU errors.

The freeze occurred when initializing Skia—specifically at SKFontManager.Default—before Avalonia loaded the App or built the MainWindow. The persistent Fontconfig cache triggered the freeze even when copied to /tmp; with a fresh cache, the same fonts worked fine. I regenerated the user cache using fc-cache -f -v, and Fontconfig reported successful completion.

Now Skia successfully enumerates the fonts, and X11 displays my app window. The build also completed successfully. I made no functional changes to the project, nor did I alter your local modifications.

[timunie]

Glad it works now. But weird issue in the end.