BuildTasks.Csc task could not be loaded from the assembly?

Question

I feel guilty asking a question like this around here, but I'm at a loss and would appreciate some help.

A proof-of-concept like web application was built on one PC and put up on a repo to download on another PC at a different location. There was originally an auto-build feature set up where Azure would build and publish automatically on check-in, but that was removed. Things were working on both ends until one side included a bulk of excluded changes. Now I'm seeing the following error:

The "Microsoft.CodeAnalysis.BuildTasks.Csc" task could not be
loaded from the assembly ...\packages\Microsoft.Net.Compilers.1.0.0\build..\tools\Microsoft.Build.Tasks.CodeAnalysis.dll. Could not load file or assembly 'file:///...\packages\Microsoft.Net.Compilers.1.0.0\tools\Microsoft.Build.Tasks.CodeAnalysis.dll' or one of its dependencies. The system cannot find the file specified. Confirm that the declaration is correct, that the assembly and all its dependencies are available, and that the task contains a public class that implements Microsoft.Build.Framework.ITask.

Does anyone have any suggestions on where to begin looking for the issue?

Answer 1

It turns out that NuGet packages were committed to the repository and breaking everything. Deleting the project\project\packages directory from the repo solved all build problems since NuGet fetches the packages automatically on build.

Answer 2

I got this error when I created a new branch for my project.

It drove me crazy for an hour. I tried most of the suggestions over the internet including the accepted answer to this question.

I then closed the project, opened it again, cleaned it and the error is gone. So this means this could be cache issue.

Anyways, just wanted to share.