After upgrade to inprocess to isoalted getting error in Mian Orch function

Hi @Jinugu, Manasa

Thank you for reaching out to Microsoft Q&A

Make sure you are following all the steps from this MS document for the migration correctly: https://dori-uw-1.kuma-moon.com/en-us/azure/azure-functions/migrate-dotnet-to-isolated-model?tabs=net8

Update your Function signature and attribute:

using Microsoft.DurableTask; // isolated

using Microsoft.Azure.Functions.Worker; // isolated worker

Update your HTTP Starter or Trigger:

using Microsoft.Azure.Functions.Worker;
using Microsoft.Azure.Functions.Worker.Http;
using Microsoft.DurableTask;
public class HttpStart
{
    [Function("HttpStart")]
    public async Task<HttpResponseData> Run(
        [HttpTrigger(AuthorizationLevel.Function, "post", "get")] HttpRequestData req,
        [DurableClient] DurableTaskClient starter,
        FunctionContext functionContext)
    {
        var instanceId = await starter.ScheduleNewOrchestrationInstanceAsync("MainOrch", input: "your input");
        var resp = req.CreateResponse(System.Net.HttpStatusCode.Accepted);
        resp.WriteString($"Started orchestration with ID = {instanceId}");
        return resp;
    }
}

Update your Function to Microsoft.Azure.Functions.Worker not Microsoft.NET.Sdk.Functions

Microsoft.Azure.Functions.Worker.Extensions.DurableTask 1.2.x or later (compatible with Durable v3)

Ensure you don’t reference Microsoft.Azure.WebJobs.Extensions.DurableTask directly in an isolated app (that’s for in‑process).

Yes, You can remove AzureWebjobsDashboard setting

In my functionapp i updated all packages, removed all webjobs dlls, updated portal settings stack and runtime etc.,. Not sure what im missing. If is it fine i can share my code and project file to review. I need quick help my deployment is in a week.

Hi Jinugu, Manasa,

System.InvalidCastException: Unable to cast object of type 'System.String' to type 'Microsoft.Azure.WebJobs.Extensions.DurableTask.IDurableOrchestrationContext'.

This error means your orchestrator is still using the old (in-process) Durable Functions binding, but the app is now running in Isolated Worker, where that binding no longer exists.

Isolated model expects:

[OrchestrationTrigger] TaskOrchestrationContext context

Because the host can't bind IDurableOrchestrationContext, it ends up passing a string

Hi @Pravallika KV , Please see my orchestration code below,its working locally.

[Function("MainOrch")]
#endif
        public async Task<List<string>> RunOrchestrator(
                     [OrchestrationTrigger] TaskOrchestrationContext context)
        {
            var logger = context.CreateReplaySafeLogger("MainOrch");
            logger.LogInformation("Starting orchestrator: MainOrch");
            try
            {
                _logger.LogInformation($"Get Downloaded Files to be processed");
                var filesToProcess = await context.CallActivityAsync<IList<ProcessingResult>>("GetPbarFileProcessingQueue", "GetPbarFileProcessingQueue");
                _logger.LogInformation($"Total Pending Files to be processed {filesToProcess.Count()}");
                var asyncTasks = new List<Task>();
                foreach (var file in filesToProcess)
                {
                    var processingTask = context.CallActivityAsync("PbarFileProcesingActivity", file);
                    asyncTasks.Add(processingTask);
                }
                await Task.WhenAll(asyncTasks);
                return new List<string>();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex.ToString());
                _traceService.TraceException(ex);
                throw;
            }
        }

Hi @Jinugu, Manasa

Your Function might be still referencing to old DLLs and Files, Can you please visit your Function App > Kudu Console > And check if there's a single app executable present, Microsoft.Azure.Functions.Worker*.dll and Microsoft.DurableTask*.dll exist. No direct project references to Microsoft.Azure.WebJobs.Extensions.DurableTask.dll

If you use WEBSITE_RUN_FROM_PACKAGE=1, the app may be running an older ZIP even after you redeploy. Toggle the setting off/on or re‑publish to force a fresh mount, then Restart.

Keep FUNCTIONS_WORKER_RUNTIME=dotnet-isolated, FUNCTIONS_EXTENSION_VERSION=~4 settings in Function app Configuration