microsoft/semantic-kernel · error · KernelException

Unable to read state from process with name '{this.State.Nam

Error message

Unable to read state from process with name '{this.State.Name}' and Id '{this.State.Id}'.

What it means

Thrown when reconstructing a KernelProcess from a DaprProcessInfo whose State is not a KernelProcessState. The top-level process object must carry a KernelProcessState; a different concrete state type signals schema or serialization drift.

Source

Thrown at dotnet/src/Experimental/Process.Runtime.Dapr/DaprProcessInfo.cs:33

[KnownType(typeof(KernelProcessStepState<>))]
public sealed record DaprProcessInfo : DaprStepInfo
{
    /// <summary>
    /// The collection of Steps in the Process.
    /// </summary>
    public required IList<DaprStepInfo> Steps { get; init; }

    /// <summary>
    /// Initializes a new instance of the <see cref="KernelProcess"/> class from this instance of <see cref="DaprProcessInfo"/>.
    /// </summary>
    /// <returns>An instance of <see cref="KernelProcess"/></returns>
    /// <exception cref="KernelException"></exception>
    public KernelProcess ToKernelProcess()
    {
        var processStepInfo = this.ToKernelProcessStepInfo();
        if (this.State is not KernelProcessState state)
        {
            throw new KernelException($"Unable to read state from process with name '{this.State.Name}' and Id '{this.State.Id}'.");
        }

        List<KernelProcessStepInfo> steps = [];
        foreach (var step in this.Steps)
        {
            if (step is DaprProcessInfo processStep)
            {
                steps.Add(processStep.ToKernelProcess());
            }
            else if (step is DaprMapInfo mapStep)
            {
                steps.Add(mapStep.ToKernelProcessMap());
            }
            else if (step is DaprProxyInfo proxyStep)
            {
                steps.Add(proxyStep.ToKernelProcessProxy());
            }
            else

View on GitHub (pinned to c028a0c7dc)

Solutions

1. Align the Semantic Kernel version used to read the process with the version that wrote it.
2. Verify JSON polymorphism / $type discriminators are configured so State deserializes as KernelProcessState for processes.
3. Inspect the persisted actor state for the process to confirm the State payload shape.
4. Clear and re-initialize the affected process instance if state was corrupted.

if (daprProcessInfo.State is not KernelProcessState)
{
    throw new InvalidOperationException($"Expected KernelProcessState but got {daprProcessInfo.State.GetType()}.");
}

public static bool IsValidProcessState(DaprProcessInfo info) =>
    info.State is KernelProcessState;

try
{
    var process = daprProcessInfo.ToKernelProcess();
}
catch (KernelException ex) when (ex.Message.Contains("Unable to read state from process"))
{
    _logger.LogError(ex, "Process state schema mismatch; check version compatibility.");
    throw;
}

When it happens

Trigger: DaprProcessInfo.ToKernelProcess() checks `this.State is KernelProcessState` and fails when the deserialized State is some other KernelProcessStepState subtype.

Common situations: Runtime version mismatch between the process that persisted state to Dapr and the runtime reading it, or a corrupted/partially-written actor state entry. Also possible after refactors that changed the state class hierarchy.

Related errors

• Unable to read state from map with name '{this.State.Name}'
• Unable to read state from proxy with name '{this.State.Name}
• Unable to deserialize KernelProcessEvent queue.
• Unable to deserialize ProcessEvent queue.
• Unable to deserialize ProcessMessage queue.

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/1e998f9591de708c. Report an issue: GitHub.