log4net.error() not executed in Global.Application_Error() after exception is thrown

Hi I code log4net in Application_Error() event in Global.asax to mail the exception message via SMTP. It works in my local PC (as always) but not working at the Win2008 IIS7 host. Not only I don't see the email, the exception doesn't even output to the text file but the INFO has output correctly. I suspect after the exception has thrown, the IIS kill the worker process and it never reach to the Application_Error() event.

I ran out of clue and hope anyone can point me to the right direction.

web.config setting
------------------
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler" requirePermission="false"></section>
<sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
<sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
<section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
<sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
<section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="Everywhere"/>
<section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
<section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
<section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
</sectionGroup>
</sectionGroup>
</sectionGroup>
</configSections>
<log4net>
<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
<param name="File" value="{Path Here}" />
<param name="AppendToFile" value="true" />
<param name="RollingStyle" value="Date" />
<param name="DatePattern" value="yyyyMMdd" />
<lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
<layout type="log4net.Layout.PatternLayout">
<param name="Header" value="[START]" />
<param name="Footer" value="[END ]" />
<param name="ConversionPattern" value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
</layout>
</appender>
<appender name="SmtpAppender" type="log4net.Appender.SmtpAppender">
<to value="{Email}" />
<from value="{Email}" />
<subject value="Exception" />
<smtpHost value="127.0.0.1" />
<bufferSize value="512" />
<lossy value="true" />
<evaluator type="log4net.Core.LevelEvaluator">
<threshold value="ERROR"/>
</evaluator>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
</layout>
</appender>
<root>
<level value="INFO" />
<appender-ref ref="RollingLogFileAppender" />
<appender-ref ref="SmtpAppender" />
</root>
</log4net>


Global.asax
-----------
private static log4net.ILog _Log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

void Application_Start(object sender, EventArgs e)
{
log4net.Config.XmlConfigurator.Configure();
}

void Application_Error(object sender, EventArgs e)
{
Exception ex = Server.GetLastError();

if (ex is HttpUnhandledException && ex.InnerException != null)
ex = ex.InnerException;

_Log.Error(ex);
}

 

Problem Solved.

I recompile the project with another machine and magically (hate to say it this way) solved the problem.

 

Well, a magic solution is better than no solution.