Server Error in '/' Application.

Value cannot be null.
Parameter name: input

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: input

Source Error:


Line 474:    public static string strip_tags(string HtmlContent)
Line 475:    {
Line 476:        return Regex.Replace(HtmlContent, @"<(.|\n)*?>", string.Empty);
Line 477:    }
Line 478:    public static string getAppPath()

Source File: d:\Webspace\taydo.vn\httpdocs\App_Code\System\Common.cs    Line: 476

Stack Trace:


[ArgumentNullException: Value cannot be null.
Parameter name: input]
   System.Text.RegularExpressions.Regex.Replace(String input, String replacement) +6672006
   System.Text.RegularExpressions.Regex.Replace(String input, String pattern, String replacement) +91
   Common.strip_tags(String HtmlContent) in d:\Webspace\taydo.vn\httpdocs\App_Code\System\Common.cs:476
   en._getMetaTag(String title, String keywords, String description) in d:\Webspace\taydo.vn\httpdocs\vn.aspx.cs:35
   en.getMetaTag() in d:\Webspace\taydo.vn\httpdocs\vn.aspx.cs:81
   en.Page_Load(Object sender, EventArgs e) in d:\Webspace\taydo.vn\httpdocs\vn.aspx.cs:232
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +51
   System.Web.UI.Control.OnLoad(EventArgs e) +95
   System.Web.UI.Control.LoadRecursive() +59
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +678


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.7.3930.0