PowerBIClient generates System.ArrayTypeMismatchException

Hey fellas!

I have som really strange issue going on. With all the latest PowerBI nuget-packages and their latest iterations of dependencies I get the following exception:

Exception thrown: 'System.ArrayTypeMismatchException' in mscorlib.dll

Additional information: Attempted to access an element as a type incompatible with the array.

The stack trace shows me this:

   at System.Collections.Generic.List`1.Add(T item)
   at Microsoft.PowerBI.Api.V1.PowerBIClient.Initialize()
   at Microsoft.PowerBI.Api.V1.PowerBIClient..ctor(ServiceClientCredentials credentials, DelegatingHandler[] handlers)
   at Apps.Kinetic.Reports.Endpoint.Service.Reports.g1u0.GenerateAccessToken(String _Reference) in D:\*masked*.cs:line 575

While trying to look into the PowerBIClient source code I found on Initialize that it does attempt to add a class of type Iso8601TimeSpanConverter to a JsonConvert list, just have a look here:

        /// </summary>
        private void Initialize()
        {
            this.Datasets = new Datasets(this);
            this.Gateways = new Gateways(this);
            this.Imports = new Imports(this);
            this.Workspaces = new Workspaces(this);
            this.Reports = new Reports(this);
            this.BaseUri = new Uri("https://api.powerbi.com");
            SerializationSettings = new JsonSerializerSettings
            {
                Formatting = Formatting.Indented,
                DateFormatHandling = DateFormatHandling.IsoDateFormat,
                DateTimeZoneHandling = DateTimeZoneHandling.Utc,
                NullValueHandling = NullValueHandling.Ignore,
                ReferenceLoopHandling = ReferenceLoopHandling.Serialize,
                ContractResolver = new ReadOnlyJsonContractResolver(),
                Converters = new List<JsonConverter>
                    {
                        new Iso8601TimeSpanConverter()
                    }
            };
            DeserializationSettings = new JsonSerializerSettings
            {
                DateFormatHandling = DateFormatHandling.IsoDateFormat,
                DateTimeZoneHandling = DateTimeZoneHandling.Utc,
                NullValueHandling = NullValueHandling.Ignore,
                ReferenceLoopHandling = ReferenceLoopHandling.Serialize,
                ContractResolver = new ReadOnlyJsonContractResolver(),
                Converters = new List<JsonConverter>
                    {
                        new Iso8601TimeSpanConverter()
                    }
            };
            CustomInitialize();
        }

Now for the love of I god I can't figure out why this is occurring in my application while in the demo sample with a few versions behind, has it fully working. But I do know that I also had it working when I at first used a regular .NET console app in 4.6.1. But now I'm using a .NET Core console app using the .NET 4.6.1 framework. Everything but this works just fine.

Here's the screenshot of the problem:

Please advice! Thanks in advance!

Update: I found this fella with a similiar issue a while back but not related to PowerBI. No answer however.

http://stackoverflow.com/questions/39339605/adding-iso8601timespanconverter-to-jsonconverter-list-throws-arraytypemismatch-e