IIS Error: Compiler Error Message: CS0433 RRS feed

  • Question

  • User-2006388156 posted

    We are upgrading a clients server from 2008 R2 Standard to 2012 R2 Standard.
    They have a web application the was developed in visual Web developer 2008 and ruining great on Server 2008.  We upgraded server 2008 to 2012 for security reasons, 2008 is EOL.
    Once the server was upgraded to 2012 we get this error. 
    The first entry ( is the this DLL used in 2008 and in our web app, but 2012 has a conflict.  How can we remove the second DLL to revolve the conflict?

    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 'Microsoft.Reporting.WebForms.LocalReport' exists in both
     'c:\Windows\Microsoft.NET\Framework64\v2.0.50727\Temporary ASP.NET Files\root\e22c2559\92c7e946\assembly\dl3\cf546f7e\10e464fc_043cd101\Microsoft.ReportViewer.WebForms.DLL'

    Source Error:

    Line 2842:        
    Line 2843:        [System.Diagnostics.DebuggerNonUserCodeAttribute()]
    Line 2844:        private void @__BuildControl__control35(Microsoft.Reporting.WebForms.LocalReport @__ctrl) {
    Line 2845:            
    Line 2846:            #line 133 "C:\inetpub\wwwroot\Report\StandardReports.aspx"

    Source File: c:\Windows\Microsoft.NET\Framework64\v2.0.50727\Temporary ASP.NET Files\root\e22c2559\92c7e946\App_Web_standardreports.aspx.1933d7c.lxenes1b.0.cs    Line: 2844

    Thursday, February 27, 2020 4:59 PM

All replies

  • User1535942433 posted

    Hi daviddobson,

    Accroding to your description,I suggest you could remove all of the files about Temporary ASP.NET Files ,then you could recompiled again your website.

    More details,you could refer to below article:


    Best regards,

    Yijing Sun

    Friday, February 28, 2020 6:39 AM
  • User281315223 posted

    Hi David,

    Based on the error, it looks like there's some temporary files lingering around that might be cached versions of the local report (i.e. some within the GAC and others from the framework itself). If that isn't an option or doesn't work, you might consider following a few of the approached detailed here, which involve things like explicitly aliasing your version or using a binding redirect to ensure the proper DLL is being targeted.

    Friday, February 28, 2020 6:53 AM