ASP.NET Core 5 Web API with Entity Framework works when running in IDE but not when published to folder and installed in IIS

Question

I have such a frustrating issue. I have authored an ASP.NET Core 5 Web API with Entity Framework Core. This runs perfectly on my dev machine and if I copy my project to another machine I can simply update the connection string and it runs there as well.

Whenever I publish the project and attempt to access it via IIS. I get the following error.

Category: Microsoft.AspNetCore.Server.IIS.Core.IISHttpServer
EventId: 2
SpanId: f97ede8e15417a59
TraceId: 7ebb4da21f77111ec887913667671c80
ParentId: 0000000000000000
RequestId: 80000017-0002-fe00-b63f-84710c7967bb
RequestPath: /api/v1/users/auth

Connection ID "18302628895834243094", Request ID "80000017-0002-fe00-b63f-84710c7967bb": An unhandled exception was thrown by the application.

Exception:
System.PlatformNotSupportedException: Strings.PlatformNotSupported_DataSqlClient

at Microsoft.Data.SqlClient.SqlConnectionStringBuilder..ctor(String connectionString)
at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerConnection.<>c.<get_IsMultipleActiveResultSetsEnabled>b__7_0(String cs)
at System.Collections.Concurrent.ConcurrentDictionary 2.GetOrAdd(TKey key, Func 2 valueFactory)
at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerConnection.get_IsMultipleActiveResultSetsEnabled()

This is my first time publishing a .net core app to IIS but I have followed a lot of guidance from the community and my swagger home page loads so this is definitely about SQL.

Below is my publishing profile. Can't figure out what I am doing wrong.

Thanks for the help.

Answer 1

I managed to resolve my own issue. It was actually clearly documented. I needed to add the following to my program.cs.