I've downloaded and ran the Godot 4.1.1 with C# support Editor for Windows and received this error
despite having the .NET SDK 6.0.414 win x64 installed in my computer.
I've deleted all other versions of the .NET SDK from my computer and performed a fresh installation of .NET SDK 6.0.414. I've even compiled the Godot with C# support step by step using the runtime documentation. All avenues still produced the error.
For testing purposes, I've downloaded the official Godot engine with C# Support and did not encounter this error. I realize that this is a newly released build and was wondering if this is a known error.