Windows 11: RuntimeBinderException: 'System.Dynamic.ExpandoObject' does not contain a definition 'MAC'

Brand new install on the latest Windows 11 with all updates, installed and reinstalled .net 6.0 and I still am getting this error on EVERY thing I run. Even scripts that work on my other PC with no problems, for some reason on this clean install, OpenBullet2 is throwing up this error.

   at CallSite.Target(Closure , CallSite , Object )
   at System.Dynamic.UpdateDelegates.UpdateAndExecute1[T0,TRet](CallSite site, T0 arg0)
   at Submission#0.<<Initialize>>d__0.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.CodeAnalysis.Scripting.ScriptExecutionState.RunSubmissionsAsync[TResult](ImmutableArray`1 precedingExecutors, Func`2 currentExecutor, StrongBox`1 exceptionHolderOpt, Func`2 catchExceptionOpt, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.Scripting.Script`1.RunSubmissionsAsync(ScriptExecutionState executionState, ImmutableArray`1 precedingExecutors, Func`2 currentExecutor, Func`2 catchExceptionOpt, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.Scripting.ScriptStateTaskExtensions.CastAsync[S,T](Task`1 task)
   at RuriLib.Models.Debugger.ConfigDebugger.Run()```

Any help would be great, thanks very much

I have the MAC entry in Environment.ini and even tried a cloned directory from another system that is working - still can’t get past the error on this clean install. I don’t understand.

It is failing right inside the Debug screen. Even though I enter MAC in the TEST DATA: field and have clearly selected MAC as the type in the Debug dropdown… There is nothing that isn’t lined up or matching. Everything is set to MAC