Crystal Reports Shows Blank Report

Crystal Reports Viewer shows a blank report on the production server but works on the development server.

The report was displaying fine and then it started to display a blank screen. This is the only thing that worked since crystal reports didn't show an error message or any other sign. I downloaded the latest version from the SAP website:

http://scn.sap.com/docs/DOC-7824

An interesting note is that the references show a version Version=13.0.2000.0
but it was really version 13.0.9.1312.  This was confusing and had me trying to uninstall and clear out the 13.0.2

Possible Solution:
Copy the folder aspnet_client to the root of your application on the server.

My Web.config file has the following:
<?xml version="1.0"?>
<configuration>
 <configSections>
        <sectionGroup name="businessObjects">
            <sectionGroup name="crystalReports">
                <section name="crystalReportViewer" type="System.Configuration.NameValueSectionHandler"/>
            </sectionGroup>
        </sectionGroup>
    </configSections>
     <appSettings>
         <add key="CrystalImageCleaner-AutoStart" value="true" />
         <add key="CrystalImageCleaner-Sleep" value="60000" />
         <add key="CrystalImageCleaner-Age" value="120000" />
     </appSettings>
     <businessObjects>
        <crystalReports>
            <crystalReportViewer>
                <add key="UseBrowserLocale" value="true"/>
                <add key="resourceURI" value="~/aspnet_client/system_web/4_0_30319/crystalreportviewers13"/>
            </crystalReportViewer>
        </crystalReports>
    </businessObjects>
  
  <system.web>
      <httpHandlers>
          <add verb="GET" path="CrystalImageHandler.aspx" type="CrystalDecisions.Web.CrystalImageHandler, CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
      </httpHandlers>
    <compilation debug="true">
      <assemblies>
        <add assembly="CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
        <add assembly="System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
        <add assembly="System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
        <add assembly="CrystalDecisions.Shared, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
        <add assembly="System.Web.Services, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
        <add assembly="log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
        <add assembly="System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
        <add assembly="System.Xml, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
        <add assembly="CrystalDecisions.ReportSource, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
        <add assembly="System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
        <add assembly="CrystalDecisions.ReportAppServer.Controllers, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
        <add assembly="CrystalDecisions.ReportAppServer.DataDefModel, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
        <add assembly="CrystalDecisions.CrystalReports.Engine, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
      <add assembly="CrystalDecisions.ReportAppServer.ClientDoc, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/></assemblies>
    </compilation>
  </system.web>
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false"/>
  <handlers>
    <add name="CrystalImageHandler.aspx_GET" verb="GET" path="CrystalImageHandler.aspx" type="CrystalDecisions.Web.CrystalImageHandler, CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" preCondition="integratedMode"/>
  </handlers></system.webServer>
    
</configuration>

C# Optional Arguments

How do you implement optional arguments or parameters in c#?
An easy way to do this is:

public boolean isValidFName(string FName, int MinLength = 0)
{
    if (FName.Length == 0 || FName.Length < MinLength)
       return false;
    else
       return true;
}



if (isValidFName(txtFName.Text))
{
    //Only checks that the first name is not length 0.
}


if (isValidFName(txtFName.Text, 5))
{
    //Checks that the first name is at least length of 5.
}