c# - Analyzer exceptions after migrating asp.net core 2.2 project to version 3.1

Question

I've followed the required steps to migrate the project from v2.2 to 3.1, upgrading nuget packages, dependencies, etc. Project runs successfully, however any change I make to the code that require to build the project or solution, a bunch of messages are shown in the console view. Take at look the below image:

How can I do to dig into the cause of those errors or check vs2019 logs files? Thanks

Answer 1

warning AD0001: Analyzer 'Microsoft.AspNetCore.Mvc.Analyzers.TopLevelParameterNameAnalyzer' threw an exception of type 'System.NullReferenceException' with message 'Object reference not set to an instance of an object.'.

While we do migration from ASP.NET Core 2.2 to 3.x, and if any installed package(s) still have 2.x dependencies, which would cause this issue.

To fix this issue, as we discussed in comment, we can double check the installed nuget packages and its dependencies to make sure all packages are also updated.