Vista - log4net: Custom appender not being invoked

I have written a custom appender to output log messages to Paul Bunyan
Service. (Paul Bunyan is a log viewer and a service from www.diamondsierra.com).
The problem that I have is I'm seeing the logs in Paul Bunyan viewer
in every environment (DEV, TEST, STAGING), except the PROD box. I
don't see any sign of loading this dll. Here is my code:

public class Log4netPaulBunyanAppender : AppenderSkeleton
{
private static ILog log = LogManager.GetLogger
(MethodBase.GetCurrentMethod().DeclaringType);
protected override void Append(log4net.Core.LoggingEvent
loggingEvent)
{
try
{
string context = null;
ThreadContextStack property =
loggingEvent.LookupProperty("NDC") as ThreadContextStack;
if ((property != null) && (property.Count > 0))
context = property.ToString();
string loggerName = loggingEvent.LoggerName;
string renderedMessage = null;
if (this.Layout == null)
renderedMessage = loggingEvent.RenderedMessage;
else
renderedMessage = base.RenderLoggingEvent
(loggingEvent);
if (context == null)
context = string.Empty;
string instanceId = loggingEvent.Properties
["InstanceId"] as string;
if (instanceId != null)
context = string.Format(format, context,
instanceId);
string pbContext = loggingEvent.Properties
["pbcontext"] as string;
if (pbContext != null)
context = string.Format(format, context,
pbContext);
string exceptionString =
loggingEvent.GetExceptionString();
if ((exceptionString != null) &&
(exceptionString.Length > 0))
renderedMessage = string.Format(format,
renderedMessage, exceptionString);
LocationInfo locInfo = null;
int lineNumber = 0;
string fileName = string.Empty;
locInfo = loggingEvent.LocationInformation;
bool isNumber = int.TryParse(locInfo.LineNumber, out
lineNumber);
fileName = locInfo.FileName;
// Log the event.
PBUtil.Log(fileName, ((isNumber) ? (UInt32)
lineNumber : (UInt32)0), loggerName, context, ConvertMessageType
(loggingEvent.Level), "{0}", new object[] { renderedMessage });
}
catch
{
// consume any exception that would arise...
}

}

private static PBMessageType ConvertMessageType(Level level)
{
PBMessageType msgType;
switch (level.Value)
{
case -2147483648:
case 0x2710:
case 0x4e20:
case 0x7530:
msgType = PBMessageType.Verbose;
break;

case 0xc350:
case 0x9c40:
msgType = PBMessageType.Informational;
break;

case 0xea60:
msgType = PBMessageType.Warning;
break;

case 0x11170:
case 0x13880:
case 0x15f90:
case 0x1d4c0:
case 0x186a0:
case 0x1adb0:
msgType = PBMessageType.Error;
break;

case 0x7fffffff:
msgType = PBMessageType.Internal;
break;

default:
msgType = PBMessageType.Error;
break;
}
return msgType;
}

override protected bool RequiresLayout
{
get { return true; }
}
}

I even tried to write to a text file using StreamWriter to see whether
this appender is being called, but I don't see any proof for it. Here
is how I configured in log4net.config file, which I use the following
code to open the config file:
XmlConfigurator.ConfigureAndWatch(new FileInfo(log4netConfigFile));

<?xml version="1.0" encoding="utf-8" ?>
<log4net>
<root>
<level value="DEBUG" />
<appender-ref ref="FileAppender" />
<appender-ref ref="PaulBunyanAppender" />
</root>
<appender name="FileAppender" type="log4net.Appender.FileAppender">
<file value="C:\pb1log.txt" />
<appendToFile value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger
[%property{NDC}] - %message%newline" />
</layout>
</appender>
<appender name="PaulBunyanAppender"
type="MyApp.Logging.Log4netPaulBunyanAppender, MyApp.Logging">
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="[%thread] - %message" />
</layout>
</appender>
</log4net>

where MyAppp.Logging.dll is the assembly and
MyApp.Logging.Log4netPaulBunyanAppender is the type.

I'm struggling with this for the past few days and any help would be
much appreciated.

Thanks.

I enabled log4net internal debugging and redirected the output to a
text file using trace listener. And I see an error message now:

log4net:ERROR [Log4netPaulBunyanAppender] Failed in DoAppend
System.IO.FileNotFoundException: The specified module could not be
found. (Exception from HRESULT: 0x8007007E)
at Pps.EnterpriseLibrary.Logging.Log4netPaulBunyanAppender.Append
(LoggingEvent loggingEvent)
at log4net.Appender.AppenderSkeleton.DoAppend(LoggingEvent
loggingEvent)

My appender is being invoked, but it's trying to find some dll, and it
could not and throws an exception. I used Red Gate's .NET Reflector
and ildasm to check the assembly and I couldn't find anything missing.
I have all the DLL's in the GAC and I also tried removing them and
linking them privately. Can somebody help me in this?


log4net: log4net assembly [log4net, Version=1.2.10.0, Culture=neutral,
PublicKeyToken=1b44e1d426115821]. Loaded from [Global Assembly Cache].
(.NET Runtime [2.0.50727.42] on Microsoft Windows NT 5.2.3790 Service
Pack 2)
log4net: DefaultRepositorySelector: defaultRepositoryType
[log4net.Repository.Hierarchy.Hierarchy]
log4net: DefaultRepositorySelector: Creating repository for assembly
[Pps.EquipmentTransfer.WebUI, Version=1.0.0.0, Culture=neutral,
PublicKeyToken=null]
log4net: DefaultRepositorySelector: Assembly
[Pps.EquipmentTransfer.WebUI, Version=1.0.0.0, Culture=neutral,
PublicKeyToken=null] Loaded From [C:\WINDOWS\Microsoft.NET\Framework
\v2.0.50727\Temporary ASP.NET Files\et\ac26e61a\1beceee5\assembly
\dl3\f3f53f44\e737e693_0997c901\Pps.EquipmentTransfer.WebUI.DLL]
log4net: DefaultRepositorySelector: Assembly
[Pps.EquipmentTransfer.WebUI, Version=1.0.0.0, Culture=neutral,
PublicKeyToken=null] does not have a RepositoryAttribute specified.
log4net: DefaultRepositorySelector: Assembly
[Pps.EquipmentTransfer.WebUI, Version=1.0.0.0, Culture=neutral,
PublicKeyToken=null] using repository [log4net-default-repository] and
repository type [log4net.Repository.Hierarchy.Hierarchy]
log4net: DefaultRepositorySelector: Creating repository [log4net-
default-repository] using type
[log4net.Repository.Hierarchy.Hierarchy]
log4net: XmlConfigurator: configuring repository [log4net-default-
repository] using file [D:\Inetpub\wwwroot\ET
\Pps.EquipmentTransfer.WebUI.log4net.config] watching for file updates
log4net: XmlConfigurator: configuring repository [log4net-default-
repository] using file [D:\Inetpub\wwwroot\ET
\Pps.EquipmentTransfer.WebUI.log4net.config]
log4net: XmlConfigurator: configuring repository [log4net-default-
repository] using stream
log4net: XmlConfigurator: loading XML configuration
log4net: XmlConfigurator: Configuring Repository [log4net-default-
repository]
log4net: XmlHierarchyConfigurator: Configuration update mode [Merge].
log4net: XmlHierarchyConfigurator: Logger [root] Level string is
[DEBUG].
log4net: XmlHierarchyConfigurator: Logger [root] level set to
[name="DEBUG",value=30000].
log4net: XmlHierarchyConfigurator: Loading Appender
[PaulBunyanAppender] type:
[Pps.EnterpriseLibrary.Logging.Log4netPaulBunyanAppender,
Pps.EnterpriseLibrary.Logging, Version=1.0.0.5,
Culture=neutral,PublicKeyToken=63073e399fa578f4]
log4net: DefaultRepositorySelector: Creating repository for assembly
[Pps.EnterpriseLibrary.Logging, Version=1.0.0.5, Culture=neutral,
PublicKeyToken=63073e399fa578f4]
log4net: DefaultRepositorySelector: Assembly
[Pps.EnterpriseLibrary.Logging, Version=1.0.0.5, Culture=neutral,
PublicKeyToken=63073e399fa578f4] Loaded From [Global Assembly Cache]
log4net: DefaultRepositorySelector: Assembly
[Pps.EnterpriseLibrary.Logging, Version=1.0.0.5, Culture=neutral,
PublicKeyToken=63073e399fa578f4] does not have a RepositoryAttribute
specified.
log4net: DefaultRepositorySelector: Assembly
[Pps.EnterpriseLibrary.Logging, Version=1.0.0.5, Culture=neutral,
PublicKeyToken=63073e399fa578f4] using repository [log4net-default-
repository] and repository type
[log4net.Repository.Hierarchy.Hierarchy]
log4net: DefaultRepositorySelector: repository [log4net-default-
repository] already exists, using repository type
[log4net.Repository.Hierarchy.Hierarchy]
log4net: PatternParser: Converter [message] Option [] Format
[min=-1,max=2147483647,leftAlign=False]
log4net: PatternParser: Converter [newline] Option [] Format
[min=-1,max=2147483647,leftAlign=False]
log4net: XmlHierarchyConfigurator: Setting Property
[ConversionPattern] to String value [[%thread] - %message [line#:
%line]]
log4net: PatternParser: Converter [literal] Option [[] Format
[min=-1,max=2147483647,leftAlign=False]
log4net: PatternParser: Converter [thread] Option [] Format
[min=-1,max=2147483647,leftAlign=False]
log4net: PatternParser: Converter [literal] Option [] - ] Format
[min=-1,max=2147483647,leftAlign=False]
log4net: PatternParser: Converter [message] Option [] Format
[min=-1,max=2147483647,leftAlign=False]
log4net: PatternParser: Converter [literal] Option [ [line#:] Format
[min=-1,max=2147483647,leftAlign=False]
log4net: PatternParser: Converter [line] Option [] Format
[min=-1,max=2147483647,leftAlign=False]
log4net: PatternParser: Converter [literal] Option []] Format
[min=-1,max=2147483647,leftAlign=False]
log4net: XmlHierarchyConfigurator: Setting Property [Layout] to object
[log4net.Layout.PatternLayout]
log4net: XmlHierarchyConfigurator: Created Appender
[PaulBunyanAppender]
log4net: XmlHierarchyConfigurator: Adding appender named
[PaulBunyanAppender] to logger [root].
log4net: XmlHierarchyConfigurator: Hierarchy Threshold []
log4net:ERROR [Log4netPaulBunyanAppender] Failed in DoAppend
System.IO.FileNotFoundException: The specified module could not be
found. (Exception from HRESULT: 0x8007007E)
at Pps.EnterpriseLibrary.Logging.Log4netPaulBunyanAppender.Append
(LoggingEvent loggingEvent)
at log4net.Appender.AppenderSkeleton.DoAppend(LoggingEvent
loggingEvent)