Logic App Standard Workflow Fails to Open in Visual Studio Designer

Question

Logic App Standard Workflow Fails to Open in Visual Studio Designer.

Error

10:52:40 AM: Starting Design Time Api
10:52:40 AM: Running command: "C:\Users\abh.verma\.azurelogicapps\dependencies\FuncCoreTools\func host start --port 8000" with pid: "24620"...

Azure Functions Core Tools
Core Tools Version:       4.0.5455 Commit hash: N/A  (64-bit)
Function Runtime Version: 4.27.5.21554

[2025-05-08T09:52:41.647Z] Error building configuration in an external startup class.
[2025-05-08T09:52:41.647Z] Error building configuration in an external startup class. Microsoft.Azure.Workflows.WebJobs.Extensions: Could not load type 'System.Runtime.InteropServices.OSPlatform' from assembly 'System.Runtime, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.
[2025-05-08T09:52:41.688Z] A host error has occurred during startup operation '710cd10b-76aa-49c3-a94c-7ccc1a087f35'.
[2025-05-08T09:52:41.688Z] Microsoft.Azure.WebJobs.Script: Error building configuration in an external startup class. Microsoft.Azure.Workflows.WebJobs.Extensions: Could not load type 'System.Runtime.InteropServices.OSPlatform' from assembly 'System.Runtime, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.
Value cannot be null. (Parameter 'provider')
[2025-05-08T09:52:41.705Z] Host startup operation has been canceled
[2025-05-08T09:52:41.731Z] Azure Storage connection string is empty or invalid. Unable to write diagnostic events.
10:57:11 AM: Error: connect ECONNREFUSED 127.0.0.1:8000

Answer 1

I have changed my host.json file like below, you also have to update the host.json in workflow-designtime as well.

"extensionBundle": {
    "id": "Microsoft.Azure.Functions.ExtensionBundle.Workflows",
    "version": "[1.*, 1.117.31)"
  }
...

Answer 2

Hi @Abhishek Verma,

I do agree with the community, The workflow designer is working and opening with below settings:

In host.json:

{

  "version": "2.0",

  "logging": {

    "applicationInsights": {

      "samplingSettings": {

        "isEnabled": true,

        "excludedTypes": "Request"

      }

    }

  },

  "extensionBundle": {

    "id": "Microsoft.Azure.Functions.ExtensionBundle.Workflows",

    "version": "[1.*, 1.117.31)"

  }

}

Or try with:

"extensionBundle": {
    "id": "Microsoft.Azure.Functions.ExtensionBundle.Workflows",
    "version": "[1.*, 2.0.0)"
 }

Then Make sure you have below value in local.settings.json:

"AzureWebJobsStorage": "UseDevelopmentStorage=true"

or

"AzureWebJobsStorage": "Storage Account Connection string"

Then when I tried to open designer, it is working for me:

---

If this answer was helpful, please click "Accept the answer" and mark Yes, as this can help other community members.

If you have any other questions or are still experiencing issues, feel free to ask in the "comments" section, and I'd be happy to help.

Answer 3

I faced the same issue and was able to resolve it by following the steps below. Here’s the solution:

1. Update the host.json file to include the following:

      {
        "version": "2.0",
        "extensionBundle": {
          "id": "Microsoft.Azure.Functions.ExtensionBundle.Workflows",
          "version": "[1.*, 2.0.0)"
        }
      }
   

2. Update the local settings by setting the function runtime to Node.js in local.settings.json:

      "FUNCTIONS_WORKER_RUNTIME": "node"
   

   By updating above, mostly you issue will be solved if not then follow the below steps.
3. If the issue persists, you can manually download the Microsoft.Azure.Functions.ExtensionBundle, then extract it to the following directory:

      {your-username}\.azure-functions-core-tools\Functions\ExtensionBundles\Microsoft.Azure.Functions.ExtensionBundle.Workflows\1.119.21
      
   

4. Set the function runtime version to: 4.0.7030

Hope this helps

Answer 4

I fixed the issue by updating the value for "AzureWebJobsStorage" in my local.settings.json :)

Azure Logic Apps (Standard) : 5.94.15
Azure Functions: 1.17.2

"AzureWebJobsStorage": <LocalAzureStorageConnectionString>

Hope that helps :)