NullReferenceExceotion når brukes i .Net6 applikasjon

[teilin]

Har oppdatert ett prosjekt som har brukt en gammel versjon av denne pakken. Når jeg da bruker nuget-pakken i .net6 applikasjonen, så ender jeg opp med en nullreference exception i System.Security.Cryptography.Xml.SignedXml. Er dette ett kjent problem?

    System.Security.Cryptography.Xml.SignedXml.IsKeyTheCorrectAlgorithm(System.Security.Cryptography.AsymmetricAlgorithm, System.Type) in SignedXml.cs
    System.Security.Cryptography.Xml.SignedXml.CheckSignedInfo(System.Security.Cryptography.AsymmetricAlgorithm) in SignedXml.cs
    System.Security.Cryptography.Xml.SignedXml.CheckSignature(System.Security.Cryptography.AsymmetricAlgorithm) in SignedXml.cs
    System.Security.Cryptography.Xml.SignedXml.CheckSignatureReturningKey(out System.Security.Cryptography.AsymmetricAlgorithm) in SignedXml.cs
    Difi.SikkerDigitalPost.Klient.XmlValidering.ResponseValidator.ValidateSignatureAndCertificate(string, string)
    Difi.SikkerDigitalPost.Klient.XmlValidering.ResponseValidator.ValidateHeaderSignature()
    Difi.SikkerDigitalPost.Klient.XmlValidering.ResponseValidator.ValidateEmptyQueueReceipt()
    Difi.SikkerDigitalPost.Klient.Api.SikkerDigitalPostKlient.SecurityValidationOfEmptyQueueReceipt(System.Xml.XmlDocument, System.Xml.XmlDocument)
    Difi.SikkerDigitalPost.Klient.Api.SikkerDigitalPostKlient.HentKvitteringOgBekreftForrigeAsync(Difi.SikkerDigitalPost.Klient.Domene.Entiteter.Kvitteringer.Kvitteringsforespørsel, Difi.SikkerDigitalPost.Klient.Domene.Entiteter.Kvitteringer.Forretning.Forretningskvittering)

I SignedXml.cs ender det opp med at expectedType er null.

private static bool IsKeyTheCorrectAlgorithm(AsymmetricAlgorithm key, Type expectedType)
        {
            Type actualType = key.GetType();

            if (actualType == expectedType)
                return true;

            // This check exists solely for compatibility with 4.6. Normally, we would expect "expectedType" to be the superclass type and
            // the actualType to be the subclass.
            if (expectedType.IsSubclassOf(actualType))
                return true;

            //
            // "expectedType" comes from the KeyAlgorithm property of a SignatureDescription. The BCL SignatureDescription classes have historically
            // denoted provider-specific implementations ("RSACryptoServiceProvider") rather than the base class for the algorithm ("RSA"). We could
            // change those (at the risk of creating other compat problems) but we have no control over third party SignatureDescriptions.
            //
            // So, in the absence of a better approach, walk up the parent hierarchy until we find the ancestor that's a direct subclass of
            // AsymmetricAlgorithm and treat that as the algorithm identifier.
            //
            while (expectedType != null && expectedType.BaseType != typeof(AsymmetricAlgorithm))
            {
                expectedType = expectedType.BaseType;
            }

            if (expectedType == null)
                return false;   // SignatureDescription specified something that isn't even a subclass of AsymmetricAlgorithm. For compatibility with 4.6, return false rather throw.

            if (actualType.IsSubclassOf(expectedType))
                return true;

            return false;
        }