[ArgumentException: Invalid postback or callback argument.  Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page.  For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them.  If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.]
   System.Web.UI.ClientScriptManager.ValidateEvent(String uniqueId, String argument) +190
   System.Web.UI.WebControls.TextBox.LoadPostData(String postDataKey, NameValueCollection postCollection) +40
   System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad) +574
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2773


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.18408

i tried contacting the manufacturer of my motherboard about this error but the guy i talked and i after a long discussion concluded it has to be something to do with the browser or the .net framework 4. This question has also been posted in the windows community as well. this error does not happen when i try visiting the same page using ie 10; but does occur with the latest version of firefox. Here is the error(s): Server Error in '/' Application. Invalid postback or callback argument. Event validation is enabled using &lt;pages enableEventValidation="true"/&gt; in configuration or &lt;%@ Page EnableEventValidation="true" %&gt; in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation. 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.ArgumentException: Invalid postback or callback argument. Event validation is enabled using &lt;pages enableEventValidation="true"/&gt; in configuration or &lt;%@ Page EnableEventValidation="true" %&gt; in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace: <pre>[ArgumentException: Invalid postback or callback argument. Event validation is enabled using &lt;pages enableEventValidation="true"/&gt; in configuration or &lt;%@ Page EnableEventValidation="true" %&gt; in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.] System.Web.UI.ClientScriptManager.ValidateEvent(String uniqueId, String argument) +190 System.Web.UI.WebControls.TextBox.LoadPostData(String postDataKey, NameValueCollection postCollection) +40 System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad) +574 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2773 Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.18408</pre>