Quick answer: Godot 4 C# project export erroring with “Mono templates not found”? Standard export templates ship without the .NET runtime — install the .NET-flavored templates separately.

A C# project builds in the editor but Export fails. The export template list doesn’t include .NET-enabled templates.

Download .NET Templates

From godotengine.org, grab the Godot Engine .NET / Mono templates matching your editor version. Editor → Manage Export Templates → Install from File.

Match Versions Exactly

Templates must match the editor minor version (4.x.y). A template for 4.3 won’t work with editor 4.4. After Godot upgrades, reinstall templates.

Per-Platform Runtime

The .NET runtime is bundled into each platform’s template. Windows ships with x64, Linux with x86_64, etc. ARM Linux / mobile may need additional setup.

Confirm in Export Window

The Export window shows each preset with a target template. .NET projects use templates labeled “dotnet” / “mono”. If only standard templates appear, the .NET ones aren’t installed.

Verifying

Export to your target platform finishes without errors. The exported binary runs the C# code at startup.

“Standard templates don’t include the .NET runtime. Install the dotnet flavor.”

Pin a specific Godot version per project — the manual reinstall step every time the editor auto-updates is otherwise a recurring pain.