System.ArgumentOutOfRangeException: Length cannot be less than zero.
Parameter name: length
   at System.String.Substring(Int32 startIndex, Int32 length)
   at ComponentPro.Website.Code.ProductFeatureGroupInfo.LoadGroups(String file, Boolean refresh)
   at CompiledRazorTemplates.Dynamic.RazorEngine_ea90a53ea7f14a2c8cc762a2e16f3288.Execute()
   at RazorEngine.Templating.TemplateBase.RazorEngine.Templating.ITemplate.Run(ExecuteContext context, TextWriter reader)
   at RazorEngine.Templating.TemplateService.Run(ITemplate template, DynamicViewBag viewBag)
   at Incredisoft.Cms.Applications.Core.Widgets.ServerCode.ServerRazorCodeBlock.OnPreRender(EventArgs e)