netcore | DNS and DHCP service written in Go , configured via etcd | DNS library

The error message already gives you some hint here:

System.NotSupportedException: The collection type 'Newtonsoft.Json.Linq.JObject' is not supported. at System.Text.Json.JsonPropertyInfoNotNullable`4.GetDictionaryKeyAndValueFromGenericDictionary(WriteStackFrame& writeStackFrame, String& key, Object& value)

As you can see, there is some Newtonsoft.Json.Linq namespace, and a System.Text.Json namespace.

Starting with ASP.NET Core 3.0, the default serializer for JSON was changed from Newtonsoft.Json to the new serializer that is built into .NET Core: System.Text.Json. There is very detailed documentation on the differences between these two serializers and how to migrate your code to System.Text.Json. But the summary here is that System.Text.Json is—by design—more limited than Newtonsoft.Json and it will not be able to serialize directly from or to those JObject or JArray objects.

Fortunately, for applications that rely on the behavior of Newtonsoft.Json or otherwise require some of its flexibility, there is a way to reconfigure the ASP.NET Core application to continue using Newtonsoft.Json for JSON serialization.

To do that, you can follow the migration guide for ASP.NET Core 3.0. Essentially you will have to reference the NuGet package Microsoft.AspNetCore.Mvc.NewtonsoftJson and then call AddNewtonsoftJson() on the MVC builder in your ConfigureServices method. For example:

You are missing the MyAppName.runtimeconfig.json file. The runtime is probably OK and already installed. You may be missing other build time config files besides this one. This file should have been in your build directory.

But MyAppName.runtimeconfig.json is usually the culprit.

Serverless table creation with the .NET Tables SDK works in REST mode only

You can try the below code,

You have a order issue source

change to:

Either use the correct key:

https://www.nuget.org/packages/FluentValidation.AspNetCore/10.2.2

The problem caused by your CI server, not by dotnet or .NET SDK .

It does not matter bicep version, you configure it by setting appropriate parameter to the resource. For Linux plans it’s LinuxFxVersion, same as in ARM, but a different syntax of writing. You need to see the app service documentation to get more details: https://docs.microsoft.com/en-us/azure/app-service/quickstart-arm-template

If you cannot figure out which property you need to set in bicep/ARM one option is to open developer tools in your browser and examine POST message sent by Portal to management.azure.com or go to resources.azure.com and see the details of the already configured (via Portal) resource or use export template functionality.

Edit:
For Windows App Service Plan setting up runtime stack is a bit complicated. Basically, there's property netFrameworkVersion which can be v3.0 v4.0 or v5.0.

However to get the core It seems you need to manipulate with metadata in sites/config:

You need to install mono-complete if you want to run software for Mono or Microsoft .NET which you are not installing from a Debian package.

Then, nstall mono-complete. In all currently supported versions of Ubuntu open the terminal and type:

Found the problem, originally VS 2019 was installed without ASP.NET and .NET Cross-Platform Development selected. Only .NET Desktop Development was selected. I created my ASP.NET projects without the proper modules installed. After noticing this I went back installed both missing modules however that did not fix the issue. Some linkages in the backend of VS 2019 weren't being made.

Final solution - reinstall VS 2019 with correct modules from the start (didn't try repair first). Now all the helpers, code-complete, Intellicode, it all works.