Targeting the specific assembly version via package reference.
Add these lines to your .csproj file to let Visual Studio handle the redirects automatically: Strange issue with System.Net.Http 4.2.0.0 not found download system.net.http.dll version 4.2.0.0
C:\Windows\Microsoft.NET\Framework\v4.0.30319\System.Net.Http.dll C:\Windows\Microsoft.NET\Framework64\v4.0.30319\System.Net.Http.dll you need to place it correctly.
The Global Assembly Cache in Windows usually holds version 4.0.0.0 , even if the underlying code is newer. ⚡ Common Fixes for the "Could Not Load" Error download system.net.http.dll version 4.2.0.0
Check the version: Right-click the file → Properties → Details. You will see .
Once you have a legitimate copy of system.net.http.dll version 4.2.0.0, you need to place it correctly.