[Bug]: dotnet and mono SDK extensions are required for the Unity debugger to work, branch: *25.08*

[RiQuY]

What Happened

I tried opening a script within Unity and I got the following error:

The below SDK extensions are required for the Unity debugger to work.
  - org.freedesktop.Sdk.Extension.dotnet
  - org.freedesktop.Sdk.Extension.mono
(arch: *x86_64*, branch: *25.08*)
Please install it from Flathub.

How to Reproduce

1. Install UnityHub from Flatpak
2. Install VSCode from Flatpak
3. Download Unity 6000.4.3f1
4. Create a Project with the Core 2D Template
5. Create an empty GameObject
6. Attach a new Script to it.
7. Double click the Script inside the Assets menu.
8. The warning message appears.

Operating System

openSUSE Tumblewed 20260327

Command-line output

No output.

Anything else?

I'm not trying to use a different external editor or custom configuration. How can I install those extensions through Flathub? Is there any possibility for this to be handled automatically by the UnityHub install?

Does this PR may solve the issue or that's unrelated #149?

[NoTuxNoBux]

I'm not trying to use a different external editor or custom configuration.

Indeed, I think this was originally done to have some measure of sane default configuration in the Unity Editor specifically for VSCode, but it does not tailor towards other editors.

How can I install those extensions through Flathub?

flatpak install dotnet
flatpak install mono

This will show you lists of extensions to choose from in various versions. Choose the 25.08 versions in this case.

Is there any possibility for this to be handled automatically by the UnityHub install?

I'm not sure but I don't think so since these are separate extension Flatpaks not part of this one. It may be that GNOME Software or similar can suggest it though - it might be possible to list them as suggestions or recommendations somewhere.

Does this PR may solve the issue or that's unrelated #149?

Probably not. The error you are seeing seems to look for the version of the base runtime that matches VSCode (25.08) and not this Flatpak specifically (24.08).

Those tips/suggestions are more aimed at VSCode to get autocompletion and debugging rather than Unity itself as Unity ships its own Mono and doesn't handle debugging in-editor.

[RiQuY]

How can I install those extensions through Flathub?

flatpak install dotnet
flatpak install mono

This will show you lists of extensions to choose from in various versions. Choose the 25.08 versions in this case.

Following your suggestion I've installed dotnet10 and mono 6 (25.08) through flatpak and the warning is gone. Can you add this to the readme below the VSCode paragraph?

Thank you, I'll close the issue since it's now solved.