2014-02-26 05:07:52,660 [TIA-WEB2SRV][Thread:23][ERROR] DotNetNuke.Services.FileSystem.FileEventHandlersContainer - Object reference not set to an instance of an object.
System.NullReferenceException: Object reference not set to an instance of an object.
   at DotNetNuke.ExtensionPoints.ExtensionPointManager.get_MefCompositionContainer()
   at DotNetNuke.ExtensionPoints.ExtensionPointManager.ComposeParts(Object[] attributeParts)
   at DotNetNuke.Services.FileSystem.FileEventHandlersContainer..ctor()
2014-02-26 08:32:26,060 [TIA-WEB2SRV][Thread:11][ERROR] DotNetNuke.UI.WebControls.CaptchaControl - System.ArgumentException: Font 'MS Sans Serif' cannot be found.
   at System.Drawing.FontFamily.CreateFontFamily(String name, FontCollection fontCollection)
   at DotNetNuke.UI.WebControls.CaptchaControl.GetFont()
2014-02-26 13:08:54,115 [TIA-WEB2SRV][Thread:13][ERROR] DotNetNuke.Services.FileSystem.FileEventHandlersContainer - Object reference not set to an instance of an object.
System.NullReferenceException: Object reference not set to an instance of an object.
   at DotNetNuke.ExtensionPoints.ExtensionPointManager.get_MefCompositionContainer()
   at DotNetNuke.ExtensionPoints.ExtensionPointManager.ComposeParts(Object[] attributeParts)
   at DotNetNuke.Services.FileSystem.FileEventHandlersContainer..ctor()
2014-02-26 14:22:18,939 [TIA-WEB2SRV][Thread:8][FATAL] DotNetNuke.Web.Common.Internal.DotNetNukeHttpApplication - System.Web.HttpException (0x80004005): A potentially dangerous Request.Path value was detected from the client (:).
   at System.Web.HttpRequest.ValidateInputIfRequiredByConfig()
   at System.Web.HttpApplication.PipelineStepManager.ValidateHelper(HttpContext context)
2014-02-26 14:34:20,331 [TIA-WEB2SRV][Thread:8][ERROR] DotNetNuke.Services.FileSystem.FileEventHandlersContainer - Object reference not set to an instance of an object.
System.NullReferenceException: Object reference not set to an instance of an object.
   at DotNetNuke.ExtensionPoints.ExtensionPointManager.get_MefCompositionContainer()
   at DotNetNuke.ExtensionPoints.ExtensionPointManager.ComposeParts(Object[] attributeParts)
   at DotNetNuke.Services.FileSystem.FileEventHandlersContainer..ctor()