LocationInformation in LoggingEvent in CustomAppendar

Question

I have written custon Appendar and override Append method. I am getting LoggingEvent in that method but when I looked at LocationInformation it is empty it shows only "?" in following properties.

protected override void Append(log4net.Core.LoggingEvent loggingEvent)
{

ClassName = loggingEvent.LocationInformation.ClassName /*contains "?"*/,
MethodName = loggingEvent.LocationInformation.MethodName /*contains "?"*/,
FileName = loggingEvent.LocationInformation.FileName /*contains "?"*/,
FullInfo = loggingEvent.LocationInformation.FullInfo /*contains "?"*/,

}

What I am doing wrong ?

Thanks