V1 to V4 .net function app conversion issue

Question

V1 to V4 .net function app conversion issue

Manish Keshvala 0

Hi,

I converted a V1 function app to a V4 .net framework 4.8 isolated function app. (contains HTTP trigger functions)

Updated the project as per Microsoft doc, however when i run it locally or publish it to Azure and invoke the HTTP endpoint through postman I get below error:

Could not load file or assembly 'file:///C:\Test\ConversionProject.dll or one of its dependencies. The system cannot find the file specified.

My .net project is called ConversionProject and i've set it to a console ap as per documentation and added the program.cs file.

Any help or pointers on what could cause the above error would be greatly appreciated.

Thanks in advance

MayankBargali-MSFT 70,986 Reputation points Moderator

2023-11-21T05:34:37.2866667+00:00

@Manish Keshvala Thanks for reaching out.

As per the error looks like the runtime is unable to locate the specified assembly file. This could be due to a number of reasons, such as incorrect file path, missing dependencies, or incorrect configuration settings.

You can validate the below :

Check if the assembly file exists in the specified location. Make sure that the file path is correct and that the file has not been moved or deleted.

Check if all the required dependencies are present in the same directory as the assembly file. If any of the dependencies are missing, you may need to add them to the project or include them in the deployment package.

Check if the configuration settings are correct. Make sure that the FUNCTIONS_WORKER_RUNTIME setting is set to dotnet-isolated and that the FUNCTIONS_EXTENSION_VERSION setting is set to ~4.

Check if the project is correctly configured to use the isolated process. Make sure that the Microsoft.NET.Sdk.Functions package is included in the project file and that the AzureFunctionsVersion property is set to v4.

You can refer to migration guide for more details.
Manish Keshvala 0 Reputation points

2023-11-21T09:15:26.2566667+00:00

Thanks Mayank for prompt reply.

The migration guide link you provided is what i followed and configuration settings are as per your advice including the project file.

I've even got the output type as Exe in project file. However because the project is now a console app when i build the project it creates the ConversionProject.exe and ConversionProject.exec.config etc but because its console no ConversionProject.dll (assembly the error is saying is missing) is created.

Wondering if it's another missing dependency as per your advice that could be causing it.

btw i created a brand new project of type .net framework isolated worker and get exactly the same error.
MayankBargali-MSFT 70,986 Reputation points Moderator

2023-11-22T10:30:41.96+00:00

@Manish Keshvala Thanks for your response and glad to know that you were able to resolve the issue.

2 answers

Your answer

MayankBargali-MSFT 70,986 Reputation points Moderator

2023-11-21T05:34:37.2866667+00:00

@Manish Keshvala Thanks for reaching out.

As per the error looks like the runtime is unable to locate the specified assembly file. This could be due to a number of reasons, such as incorrect file path, missing dependencies, or incorrect configuration settings.

You can validate the below :

Check if the assembly file exists in the specified location. Make sure that the file path is correct and that the file has not been moved or deleted.

Check if all the required dependencies are present in the same directory as the assembly file. If any of the dependencies are missing, you may need to add them to the project or include them in the deployment package.

Check if the configuration settings are correct. Make sure that the FUNCTIONS_WORKER_RUNTIME setting is set to dotnet-isolated and that the FUNCTIONS_EXTENSION_VERSION setting is set to ~4.

Check if the project is correctly configured to use the isolated process. Make sure that the Microsoft.NET.Sdk.Functions package is included in the project file and that the AzureFunctionsVersion property is set to v4.

You can refer to migration guide for more details.
Manish Keshvala 0 Reputation points

2023-11-21T09:15:26.2566667+00:00

Thanks Mayank for prompt reply.

The migration guide link you provided is what i followed and configuration settings are as per your advice including the project file.

I've even got the output type as Exe in project file. However because the project is now a console app when i build the project it creates the ConversionProject.exe and ConversionProject.exec.config etc but because its console no ConversionProject.dll (assembly the error is saying is missing) is created.

Wondering if it's another missing dependency as per your advice that could be causing it.

btw i created a brand new project of type .net framework isolated worker and get exactly the same error.
MayankBargali-MSFT 70,986 Reputation points Moderator

2023-11-22T10:30:41.96+00:00

@Manish Keshvala Thanks for your response and glad to know that you were able to resolve the issue.

Answer 1

@Manish Keshvala

I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this! Since the Microsoft Q&A community has a policy that The question author cannot accept their own answer. They can only accept answers by others, I'll repost your solution in case you'd like to "Accept" the answer.

Issue:

You try to convert your V1 function app to a V4 .net framework 4.8 isolated function app. (contains HTTP trigger functions) and observed that when you run it locally or publish it to Azure and invoke the HTTP endpoint through postman you get below error: Could not load file or assembly 'file:///C:\Test\ConversionProject.dll or one of its dependencies. The system cannot find the file specified.

Solution:

You found the github issue : https://github.com/Azure/azure-functions-dotnet-worker/issues/2072 and you rolled back Microsoft.Azure.Functions.Worker.Sdk to 1.15.1 from 1.16.2 and confirmed that the issue is resolve. When using latest package when you set FunctionsEnableWorkerIndexing attribute in the project file as below which resolves the issue with latest package. <FunctionsEnableWorkerIndexing>False</FunctionsEnableWorkerIndexing>

Thank you again for your time and patience throughout this issue.

Answer 2

I had the latest nuget packages in my project, however after i rolled back the version of Microsoft.Azure.Functions.Worker.Sdk to 1.15.1 from 1.16.2, i can now get the function app to run locally and after publishing it to Azure resources.

When a colleague of mine created a new project on his machine it added the 1.15.1 nuget package and ran successfully, then found below solution to use latest package but with a FunctionsEnableWorkerIndexing attribute in the project file.

https://github.com/Azure/azure-functions-dotnet-worker/issues/2072

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V1 to V4 .net function app conversion issue

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