The type ‘HttpClient’ exists in both ‘System.Net.Http, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’ and ‘System.Net.Http, Version=4.0.0.0

The type ‘HttpClient’ exists in both ‘System.Net.Http, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’ and ‘System.Net.Http, Version=4.0.0.0

If you encounter this bug simply upgrade your .NET Project to 4.7.2. This is a bug in 4.7.1.

See Release notes: https://github.com/Microsoft/dotnet/blob/master/releases/net472/dotnet472-changes.md#bcl

Increment the assembly version of System.Net.Http and System.IO.Compression to be compatible with netstandard 2.0 and the compatibility package. [504519, mscorlib.dll, Feature]

Enjoy!