log4net logger.File property. Error: "The given path's format is not supported."

[Ravi L]

I need to configure log4net programmatically. I got the code for this from the net which lots of users happen are using. But when I get an error saying "The given path's format is not supported." at logger.ActivateOptions. the code is reproduced below:

public class Logger
{
        private PatternLayout _layout = new PatternLayout();
        private const string LOG_PATTERN = "%d [%t] %-5p %m%n";
 
        public string DefaultPattern
        {
                get { return LOG_PATTERN; }
        }
 
    public Logger()
    {
        _layout.ConversionPattern = DefaultPattern;
        _layout.ActivateOptions();
    }
 
    public PatternLayout DefaultLayout
    {
        get { return _layout; }
    }
 
    public void AddAppender(IAppender appender)
    {
        Hierarchy hierarchy = 
                (Hierarchy)LogManager.GetRepository();
 
        hierarchy.Root.AddAppender(appender);
    }
 
    static Logger()
    {
        try
        {
            Hierarchy hierarchy = (Hierarchy)LogManager.GetRepository();            
            PatternLayout patternLayout = new PatternLayout();
 
 
            RollingFileAppender roller = new RollingFileAppender();            
            roller.AppendToFile = true;
            roller.RollingStyle = RollingFileAppender.RollingMode.Size;
            roller.MaxSizeRollBackups = 4;
            roller.MaximumFileSize = "10000KB";
            roller.StaticLogFileName = true;            
            roller.File = "c:\\errorlog\\dnservices.log";
 
            patternLayout.ConversionPattern = LOG_PATTERN;
            patternLayout.ActivateOptions();
            roller.Layout = patternLayout;
            roller.ActivateOptions();
            hierarchy.Root.AddAppender(roller);
 
            hierarchy.Root.Level = Level.All;
            hierarchy.Configured = true;
        }
        catch (Exception)
        {            
            throw;
        }
    }
 
    public static ILog Create()
    {
        return LogManager.GetLogger("Logger");
    }
}

I am using Visual Studio 2010 for development. Will this make any difference. the log4net version is 1.2.0.10. Have spent a lot of time on this to end up with this error. Any help would be appreciated.

Thank you.

Ravi