Q:

http error 500.19 - Internal server error

I am trying to get an application (that I didn't develop) running on a windows 2008 r2 64-bit server running IIS 7.5.
I am getting the above stated error - here are more details - 
The requested page cannot be accessed because the related configuration data for the page is invalid
Error Code 0x8007007e

I know that the server can access the web.config, because if I make changes to it, the error code changes.
I also know that it is a correct web.config, because it is running successfully on a different server with the same file.
Does anyone have any idea what might be causing this.  The error message I am getting really doesn't tell me anything.  
I have tried using FailedRequestTracing, but either I don't know how to read those logs or there is no more information there. There are also no errors in the event logs on the server.
Where else can I look to get a better idea of what is happening?
Thanks for any thoughts....
EDIT - Here is the web.config.  As I said earlier, it is strange that it is working on another server.  I checked to ensure are referenced assemblies are available (as according to the page here, it appear that may be the problem) in the gac.  
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <appSettings>
        <add key="ChartImageHandler" value="storage=file;timeout=20;dir=c:\temp\;deleteAfterServicing=false;" />
    </appSettings>
    <connectionStrings>
        <!-- removed for this post -->

    </connectionStrings>
    <system.data>
        <DbProviderFactories>
            <!--<add name="IBM Informix .NET Data Provider 3.0.0" invariant="IBM.Data.Informix.3.0.0" description="IBM Informix Data Provider 3.0.0 for .NET Framework 2.0" type="IBM.Data.Informix.IfxFactory, IBM.Data.Informix.3.0.0, Version=3.0.0.2, Culture=neutral, PublicKeyToken=7c307b91aa13d208"/>-->
        </DbProviderFactories>
    </system.data>
    <system.web>
        <httpRuntime maxRequestLength="8192" />
        <customErrors mode="Off" />
        <sessionState timeout="360" />
        <pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID">
            <namespaces>
                <clear />
            </namespaces>
            <controls>
                <add tagPrefix="asp" namespace="System.Web.UI.DataVisualization.Charting" assembly="System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
            </controls>
        </pages>
        <!--
          Set compilation debug="true" to insert debugging
          symbols into the compiled page. Because this
          affects performance, set this value to true only
          during development.
    -->
        <compilation debug="true" targetFramework="4.0">
            <assemblies>
                <add assembly="System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" /></assemblies></compilation>
        <httpHandlers>
            <add path="ChartImg.axd" verb="GET,HEAD" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false" />
        </httpHandlers>
    </system.web>
    <system.web.extensions>
        <scripting>
            <webServices>
                <jsonSerialization maxJsonLength="5000000" />
            </webServices>
        </scripting>
    </system.web.extensions>
    <system.webServer>
        <validation validateIntegratedModeConfiguration="false" />
        <handlers>
            <remove name="ChartImageHandler" />
            <add name="ChartImageHandler" preCondition="integratedMode" verb="GET,HEAD" path="ChartImg.axd" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
        </handlers>
        <defaultDocument>
            <files>
                <add value="index.aspx" />
            </files>
        </defaultDocument>
        <tracing>
            <traceFailedRequests>
                <add path="*.aspx">
                    <traceAreas>
                        <add provider="ASP" verbosity="Verbose" />
                        <add provider="ASPNET" areas="Infrastructure,Module,Page,AppServices" verbosity="Verbose" />
                        <add provider="ISAPI Extension" verbosity="Verbose" />
                        <add provider="WWW Server" areas="Authentication,Security,Filter,StaticFile,CGI,Compression,Cache,RequestNotifications,Module,FastCGI" verbosity="Verbose" />
                    </traceAreas>
                    <failureDefinitions timeTaken="00:00:00" statusCodes="400-600" />
                </add>
            </traceFailedRequests>
        </tracing>
    </system.webServer>
</configuration>

A:

I was able to get past this error by disabling compression that is applied by having wsus on the server.
See details here.
Thanks for everyone's help.

