Azure App Service and VB.NET exe Issue

Question

I have web application deployed on azure using Azure App service (WebApps). The application is built in .NET CORE 3.1 and Angular framework and the process calls another exe in the backend which is developed in VB.NET.

That VB.NET exe is responsible for reading from an excel file, applying some formulas on the excel data (which are defined in the excel) and writing to another excel file.
Everything works fine except when the program runs the VB.NET exe it crashes and does not run completely on Azure. The same works fine on my local machine. Since I am using WebApp service so the error is not displayed to me either.

What can I do to resolve this? Is there some special steps that needs to be taken to work with excel macros or some different kind of service that I need to use?

Also, I created a dummy exe in .NET CORE 3.1 which creates, writes to an excel file and waits 30 seconds and ends. I called that from my web application and that worked completely fine on Azure.
Is this just a technology issue that Azure doesn't support VB.NET applications so the only solution is to re-write the exe in C# .NET Core. Or is there some package installation needed or some other way I can get that to work.

Answer 1

Azure AppService does not support Interop that was used by the application to perform excel functions. The solution is to create a VM server, deploy the site there and install excel. So the whole environment is created for the exe to run properly.