NUnit Console 3.20.2 no longer works with `--framework=mono-4.0`

[viniciusjarina]

3.20.2 no longer works with Mono

On 3.20.1:

nuget install NUnit.ConsoleRunner -Version 3.20.1 -source "https://api.nuget.org/v3/index.json" -OutputDirectory .

mono NUnit.ConsoleRunner.3.20.1/tools/nunit3-console.exe ./tests/MyTests.dll --framework=mono-4.0

Works fine

On 3.20.2:

nuget install NUnit.ConsoleRunner -Version 3.20.2 -source "https://api.nuget.org/v3/index.json" -OutputDirectory .

mono NUnit.ConsoleRunner.3.20.2/tools/nunit3-console.exe ./tests/MyTests.dll --framework=mono-4.0

Got an exception:

NUnit Console Runner 3.20.2 (Release)
Copyright (c) 2022 Charlie Poole, Rob Prouse
Friday, December 5, 2025 5:08:40 PM

Runtime Environment
   OS Version: MacOSX 25.1.0.0 
   Runtime: .NET Framework CLR v4.0.30319.42000

Test Files
    ./tests/MyTests.dll 


Errors, Failures and Warnings

1) Error : 
System.ArgumentException : The net-4.6 framework is not available for X86=False.
Available frameworks: mono-4.0 netcore-7.0 netcore-9.0 netcore-10.0
--ArgumentException
The net-4.6 framework is not available for X86=False.
Available frameworks: mono-4.0 netcore-7.0 netcore-9.0 netcore-10.0
  at NUnit.Engine.Services.TestAgency.GetAgent (NUnit.Engine.TestPackage package) [0x000ce] in <6703968c84874674a45903e2c145866b>:0 
  at NUnit.Engine.Runners.ProcessRunner.CreateAgentAndRunnerIfNeeded () [0x0003d] in <6703968c84874674a45903e2c145866b>:0 
  at NUnit.Engine.Runners.ProcessRunner.RunTests (NUnit.Engine.ITestEventListener listener, NUnit.Engine.TestFilter filter) [0x0001f] in <6703968c84874674a45903e2c145866b>:0 

I am using Mono JIT compiler version 6.12.0.206 on macOS 26.1