Resolving View State Message Authentication Code MAC Errors RRS feed

  • Question

  • User625300256 posted

    The commercial web hosting company now supports my application with a server farm. The link, above, discusses a problem a security fix introduced and how to fix the problem. It seems there is a mechanism by which variables in the application are persisted by putting them in a package and sending the package back and forth between the browser and the server. In a server farm, as load increases, it is possible for one web session to be handled by more than one server. The security fix assumes all interaction will occur on a particular server. When it does not occur on a particular server the end user's interaction becomes unsatisfactory. The package and the server are lashed together with a MAC address. When the MAC address changes, as it would when the load master moves the session to a different server, there is a malfunction. The Microsoft solution is to specify the MAC address in Web.config. That way the application provides the MAC address, not the hardware on which the application is running. I followed directions and generated the XML (PowerShell) that goes into the Web.config file and put the XML where I was told to put it. After that the application refused to run. Presumably there is a syntax error in Web.config. Do you have any idea what is wrong with this Web.config file? Thanks.


    <?xml version="1.0"?>

    For more information on how to configure your ASP.NET application, please visit


    <machineKey decryption="AES" decryptionKey="4B3E85D9CED6F125761D7E982855CBE192868631112152CF0EE230773287B185" validation="HMACSHA256"

    validationKey="ED9A1B8121BC4AAE042C572692C02E086936918836EED4210492B797528B29FFCAA99F1E9226C7B7C30B6EFE2F57E5DC6DADE7EC3C4C6ADAFDBB861BB314C7E2" />
    <compilation debug="true" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" />


    Friday, July 26, 2019 11:17 PM

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