.deps.json could not be found

Question

Follow this menu sequence:

File -> New -> Project -> ASP>NET Core Web Application (.Net Framework)

Build -> Build Solution

Get this error:

Error

Answer 1

In my case, the problem was that I tried to run unit tests using a dll from the ref folder.

As described by Pavol Kovalik in https://developercommunity.visualstudio.com/solutions/1270375/view.html:

Mine was caused by having 2 Project.Tests.dll files in build artifact directory

...\Debug
  net5.0
    ref
      Project.Tests.dll
    Project.Tests.dll
    Project.Tests.deps.json 

As such the vstest was discovering 2 test files. First without deps.json file and another with it. My fix was to enforce that test file is in net* directory (could be net5.0 or net48 in my case) like this

- script: |
    dotnet vstest $(Build.BinariesDirectory)/bin/**/net*/*.Tests.dll --logger:trx
  displayName: Execute unit tests