Validating a resource with CodeableReference throws an exception System.InvalidOperationException: 'Checking reference type should have been handled already.'

[almostchristian]

We're currently evaluating moving to the new validator and found a bug when the resource as a CodeableReference property.
The code for validating references does not handle CodeableReference values properly throws an exception.

Reproduction code:

var packageServer = "https://packages.simplifier.net";
var fhirRelease = FhirRelease.R5;
var packageResolver = FhirPackageSource.CreateCorePackageSource(ModelInfo.ModelInspector, fhirRelease, packageServer);
var resourceResolver = new CachedResolver(packageResolver);
var terminologyService = new LocalTerminologyService(resourceResolver);

var validator = new Validator(resourceResolver, terminologyService);
var testEncounter = new Encounter
{
    ServiceType = [ new CodeableReference { Concept = new CodeableConcept("http://hl7.org/fhir/ValueSet/service-type", "test") } ],
};

var profile = Firely.Fhir.Validation.Canonical.ForCoreType("Encounter").ToString();

Exception:

System.InvalidOperationException: 'Checking reference type should have been handled already.'

   at Firely.Fhir.Validation.ReferencedInstanceValidator.Validate(IScopedNode input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.AssertionValidators.<ValidateMany>g__repeat|4_0(IValidatable assertion, IEnumerable`1 input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.AssertionValidators.ValidateMany(IAssertion assertion, IEnumerable`1 input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.AllValidator.<>c__DisplayClass12_0.<Validate>b__0(IAssertion ma)
   at System.Linq.Enumerable.SelectArrayIterator`2.Fill(ReadOnlySpan`1 source, Span`1 destination, Func`2 func)
   at System.Linq.Enumerable.SelectArrayIterator`2.ToList()
   at Firely.Fhir.Validation.AllValidator.Validate(IEnumerable`1 input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.AssertionValidators.ValidateMany(IAssertion assertion, IEnumerable`1 input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.ElementSchema.<>c__DisplayClass19_0.<ValidateInternal>b__0(IAssertion ma)
   at System.Linq.Enumerable.WhereSelectListIterator`2.ToList()
   at Firely.Fhir.Validation.ElementSchema.ValidateInternal(IEnumerable`1 input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.ElementSchema.Firely.Fhir.Validation.IGroupValidatable.Validate(IEnumerable`1 input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.AssertionValidators.ValidateMany(IAssertion assertion, IEnumerable`1 input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.ChildrenValidator.<>c__DisplayClass13_0.<Validate>b__0(Match m)
   at System.Linq.Enumerable.SelectListIterator`2.MoveNext()
   at System.Collections.Generic.List`1.AddRange(IEnumerable`1 collection)
   at Firely.Fhir.Validation.ChildrenValidator.Validate(IScopedNode input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.AssertionValidators.ValidateOne(IAssertion assertion, IScopedNode input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.ElementSchema.<>c__DisplayClass21_0.<ValidateInternal>b__0(IAssertion ma)
   at System.Linq.Enumerable.WhereSelectListIterator`2.ToList()
   at Firely.Fhir.Validation.ElementSchema.ValidateInternal(IScopedNode input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.FhirSchema.ValidateInternal(IScopedNode input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.ResourceSchema.<>n__0(IScopedNode input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.ResourceSchema.<>c__DisplayClass5_0.<ValidateResourceSchema>b__0()
   at Firely.Fhir.Validation.ValidationLogger.Start(ValidationState state, String profileUrl, Func`1 validator)
   at Firely.Fhir.Validation.ResourceSchema.ValidateResourceSchema(IScopedNode input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.ResourceSchema.<>c__DisplayClass4_0.<ValidateInternal>b__6(ResourceSchema s)
   at System.Linq.Enumerable.SelectEnumerableIterator`2.ToList()
   at Firely.Fhir.Validation.ResourceSchema.ValidateInternal(IScopedNode input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.ResourceSchema.<>c__DisplayClass3_0.<ValidateInternal>b__0(IScopedNode i, Int32 index)
   at System.Linq.Enumerable.<SelectIterator>d__229`2.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Firely.Fhir.Validation.ResourceSchema.ValidateInternal(IEnumerable`1 input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.SchemaReferenceValidator.Validate(IEnumerable`1 input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.SchemaReferenceValidator.Validate(IScopedNode input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.AssertionValidators.ValidateOne(IAssertion assertion, IScopedNode input, ValidationSettings vc, ValidationState state)
   at Firely.Fhir.Validation.AssertionValidators.Validate(IAssertion assertion, IScopedNode input, ValidationSettings vc)
   at Firely.Fhir.Validation.Validator.Validate(IScopedNode sn, String profile)
   at Firely.Fhir.Validation.Validator.Validate(Resource instance, String profile)
   at Program.<Main>$(String[] args) in U:\source\ConsoleApp1\ConsoleApp1\Program.cs:line 66