Export Crystal Report Crash Application from C# 4.0 App. Throw Unhandled exception

Using C# 4.0 Winform Application(32 bit) with Crystal Report 2011 with Crystal report .Net runtime "CRRuntime_32bit_13_0_16".

During exporting report into PDF. An unhandled win32 exception occurred.

A few time this works and next time throw unhandled error as below

Problem signature:

Problem Event Name: APPCRASH

Application Name: Application.vshost.exe

Application Version: 10.0.30319.1

Application Timestamp: 4ba2084b

**Fault Module Name: MSVCR80.dll**

Fault Module Version: 8.0.50727.6229

Fault Module Timestamp: 4ec352ab

Exception Code: c0000005

Exception Offset: 000173c1

OS Version: 6.1.7601.2.1.0.256.48

I am exporting this first then sending the file in mail as attachment.

Then I delete the file after export to pdf process end.

Once this process finished only then user is able to do another process.

The sample code is as below

    if (m_ReportDocument != null)

    m_ReportDocument.ExportToDisk(ExportFormatType.PortableDocFormat, fileName);

    if (!File.Exists(fileName))

    { if (m_ReportDocument != null)

    m_ReportDocument.Dispose();

    return false;

    }