Server Error in '/' Application.

Value cannot be null.
Parameter name: String

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: String

Source Error:

Line 68:         ServicePointManager.ServerCertificateValidationCallback += new RemoteCertificateValidationCallback(acc8.App_Code.utility.ValidateCertificate);Line 69:Line 70:         int Status = zp.PaymentRequest("e2ceb5fa-0c24-11e9-a75f-005056a205be", Int32.Parse((string)Session["amountTotal"]) / 10, "خرید اینترنتی زرین پال", "", "", CallBackUrl, out Authority);Line 71: Line 72:         if (Status == 100)

Source File: c:\inetpub\wwwroot\test-z\Default.aspx    Line: 70

Stack Trace:

[ArgumentNullException: Value cannot be null.Parameter name: String]System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal) +14286574System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info) +174ASP.test_z_default_aspx.DoPay() in c:\inetpub\wwwroot\test-z\Default.aspx:70ASP.test_z_default_aspx.Page_Load(Object sender, EventArgs e) in c:\inetpub\wwwroot\test-z\Default.aspx:37System.Web.UI.Control.OnLoad(EventArgs e) +108System.Web.UI.Control.LoadRecursive() +90System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1533


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4330.0