Resolved: “CS0433: The type X exists in both A and B” error in Visual Studio with DevExpress

You may run into this error after upgrading DevExpress version of your .NET project through DevExpress Project Converter:

Server Error in ‘/’ Application.

Compilation Error

Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS0433: The type ‘DevExpress.Web.ASPxClasses.Paddings’ exists in both ‘c:\Windows\Microsoft.NET\assembly\GAC_MSIL\DevExpress.Web.v13.1\v4.0_13.1.5.0__b88d1754d700e49a\DevExpress.Web.v13.1.dll’ and ‘c:\Users\Nedim\AppData\Local\Temp\Temporary ASP.NET Files\root\2469c78b\489019cf\assembly\dl35b06e65\48aa4dfb_0a84ce01\DevExpress.Web.v12.2.DLL’

Type error after DevExpress project convertion
Type error after DevExpress project convertion


Close Visual Studio and clear bin and obj folders in your project directory which was this path in my case: C:\Users\Nedim\Documents\Visual Studio 2012\Projects\projectname\projectname

If it doesn’t work, try these steps:

  • Restart IIS
  • Clear the content of these folders:
    C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\
    C:\WINDOWS\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\
  • Delete¬†App_Licenses.dll file in your solution
  • Rebuild your project