Page Error

<link rel="stylesheet" href="/NETQuest/Styles/Accounts.CSS"><h1>Page Error</h1><hr/>An unexpected error has occurred on this page. The system administrators have been notified. Please feel free to contact us with the information surrounding this error.<br/>The error occurred in: http://mmol.m3-mi.com/MarsMedicalApp/login/login.aspx?__hstc=143501546.93c694cca413846cc31a26b1fc343618.1635778944904.1637265659315.1637679461273.13&__hssc=143501546.11.1637679461273&__hsfp=1036951284<br/>Error Message: <font class="ErrorMessage">Value cannot be null.
Parameter name: value</font><hr/><b>Stack Trace:</b><br/>System.ArgumentNullException: Value cannot be null.
Parameter name: value
   at System.String.IndexOf(String value, Int32 startIndex, Int32 count, StringComparison comparisonType)
   at System.String.Contains(String value)
   at KMRS.CommonLibrary.UserAgentHandler.TestCase.Test()
   at KMRS.CommonLibrary.UserAgentHandler.TestCase.Test()
   at KMRS.CommonLibrary.UserAgentHandler.isCompatible()
   at login.UserAgentTest()
   at login.Page_Load(Object sender, EventArgs e)
   at System.EventHandler.Invoke(Object sender, EventArgs e)
   at System.Web.UI.Control.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)