ReportViewer.LocalReport.SetParameters() fails after a report has been
exported to a file location that no longer exists (media removed,
invalid path, etc.).

Microsoft.Reporting.WinForms.LocalProcessingException: An error
occurred during local report processing. --->
Microsoft.Reporting.DefinitionInvalidException: The definition of the
report 'Main Report' is invalid. --->
Microsoft.ReportingServices.ReportProcessing.ReportProcessingException:
An unexpected error occurred in Report Processing. --->
System.Runtime.InteropServices.ExternalException: Cannot execute a
program. The command being executed was "c:\WINDOWS\Microsoft.NET
\Framework\v2.0.50727\vbc.exe" /noconfig @"C:\Documents and Settings
\...\Temp\_c0gtdjg.cmdline".

To demonstrate you will need a win forms app with a main form and a
second form with the ReportViewer control. A button on the main form
launches the report form and populates the control with data and sets
report parameters.

Run the app, navigate to the report form and display the report. Now
Export to PDF to some sort of removable media. Close the report form
but not the application. Remove the media. Navigate back to the
report form. The above exception occurs when attempting to
SetParameters().

I can catch the exception, but I can not figure out a way to cleanly
recover. The only recovery is to exit the application and go back
in. It will attempt to access the non-existent media, but it doesn't
throw an exception.

I have found a workaround:

try {
this.reportViewer.LocalReport.SetParameters(reportParameters);
}
catch {
// Set directory to any valid path.
// The actual path doesn't seem to influence the Export dialog:
System.IO.Directory.SetCurrentDirectory(anyValidDirectoryPath);

// Try again:
this.reportViewer.LocalReport.SetParameters(reportParameters);
}

Hope this helps prevent someone from blowing an entire afternoon on a