Grpc.Core.RpcException "Failed to deserialize response message.." or "InvalidOperationException: Length mismatch"

I am using Visual Studio 2022 Preview and I am facing this problem.

As mentioned here, there is a bug in Visual Studio 2022.

I applied the following work around mentioned and it worked for me. See the screen shots below.

Set 'Hot Reload CSS changes' to false as follows.

Frankly, this sounds like a bug in protobuf-net that you should log on GitHub, ideally with a repro that also shows the service contract (interface).

The types should look reasonable. The length mismatch at the end is particularly alarming, but I do not believe that this has any relationship to the dynamic types discussion.

Happy to help investigate here (I'm the author), but: this sounds more like a GitHub thing.

I suspect that the length difference is related to Data not being a proto-contract (so it is questionable as to whether the proto-include is being respected; this is reinforced by the var that there would be duplicate fields 1 if it were), but a proper repro would really help.

The following seems to work - the only changes to your code is to make sure that Data is marked as a ProtoContract, use a different number for the "include" part, and to add a Create method to PersonDataItem for the test harness to use; it is hard to know how much of the problem this accounts for without a repro.

using ProtoBuf;
using ProtoBuf.Meta;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization;

[DataContract]
public class Response<TValue>
{
    [DataMember(Order = 1)]
    public TValue Value;
}

[DataContract]
public class PersonData : Data
{
    [DataMember(Order = 1)]
    public IList<PersonDataItem> PersonDataList;
}

[DataContract]
public class PersonDataItem
{
    public static PersonDataItem Create(PersonDataType type, DateTime? time)
        => new PersonDataItem { Type = type, Time = time };
    [DataMember(Order = 1)]
    public PersonDataType Type { get; private set; }

    [DataMember(Order = 2)]
    public DateTime? Time { get; private set; }


    [DataContract]
    public enum PersonDataType : int
    {

        [EnumMember]
        Child = 1,
        [EnumMember]
        Adult = 2
    }
}

[ProtoContract, DataContract]
[ProtoInclude(10, typeof(PersonData))]
public class Data
{
    [ProtoMember(1), DataMember(Order = 1)]
    public string Name;
}

static class P
{
    static void Main()
    {
        var resp = new Response<PersonData>
        {
            Value = new PersonData
            {
                Name = "abc",
                PersonDataList = new List<PersonDataItem>
                {
                    PersonDataItem.Create(PersonDataItem.PersonDataType.Adult, DateTime.Now),
                }
            }
        };
        var clone = RoundTrip(resp);
        Console.WriteLine(clone.Value.Name);
        var item = clone.Value.PersonDataList.Single();
        Console.WriteLine(item.Time);
        Console.WriteLine(item.Type);
    }
    static T RoundTrip<T>(T value)
    {
        var model = RuntimeTypeModel.Default;
        using var state = model.Measure<T>(value);
        using var ms = new MemoryStream();
        state.Serialize(ms); // we expect this to explode if there was a length mismatch
        ms.Position = 0;
        return model.Deserialize<T>(ms);
    }
}

There are two causes for this error

1. If you are using IIS to host the gRPC server there are some features that are not yet supported in ISS hence using Kestrel instead should fix the bug.
2. Explained by @vivekDev there is a bug in Visual Studio 2022 preview and turning off Hot Reload For Css should fix the bug