Could not load file or assembly 'System.Net.Http, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The located assembly's manifest definition does not mat

Could not load file or assembly 'System.Net.Http, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

莫名其妙的错误，耗费我半天没解决。之前系统一切好好的，发生原因没找到，找到了 解决方案。

按下面配置 web.config 或者 app.config ，重启IIS即可。