.net core 3.0 Could not load file or assembly 'System.Web.Http Version=5.2.7.0'

Question

I've migrated my WebApi project from .net core 2.2 to .net core 3.0 version. I was following this article: https://docs.microsoft.com/en-us/aspnet/core/migration/22-to-30?view=aspnetcore-3.0&tabs=visual-studio#mvc-service-registration

I was able to build project but I'm getting an exception at runtime:

Unable to load one or more of the requested types. Could not load file or assembly 'System.Web.Http, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. The system cannot find the file specified.

Did anyone have same issues? Do you know which nuget package am I missing?

did you try this, stackoverflow.com/questions/27250581/… or any number of these — TheGeneral
@TheGeneral I didn't have such issues on .net core 2.2. So this is something specific with .net core 3.0 — Algirdas

Algirdas Algirdas · Accepted Answer · 2019-11-26T09:55:34

One of our internal nuget package was not migrated to support .net core 3. That cause runtime exception. We migrated nuget package and problem is fixed. The strange thing is that there was no compile warning.

.net core 3.0 Could not load file or assembly 'System.Web.Http Version=5.2.7.0'

Unable to load one or more of the requested types. Could not load file or assembly 'System.Web.Http, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. The system cannot find the file specified.

1 Answers