Operation is not valid due to the current state of the object.

I am getting the below error while binding a gridview.

Operation is not valid due to the current state of the object.

[InvalidOperationException: Operation is not valid due to the current state of the object.]
   System.Web.HttpValueCollection.ThrowIfMaxHttpCollectionKeysExceeded() +2692482
   System.Web.HttpValueCollection.FillFromEncodedBytes(Byte[] bytes, Encoding encoding) +61
   System.Web.HttpRequest.FillInFormCollection() +148

[HttpException (0x80004005): The URL-encoded form data is not valid.]
   System.Web.HttpRequest.FillInFormCollection() +206
   System.Web.HttpRequest.get_Form() +68
   System.Web.HttpRequest.get_HasForm() +8743911
   System.Web.UI.Page.GetCollectionBasedOnMethod(Boolean dontReturnNull) +97
   System.Web.UI.Page.DeterminePostBackMode() +63
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +133

This error occurs when form fields are very large in numbers.By default, the maximum value of MaxHttpCollection is 1000.

To solve this error, increase MaxHttpCollection value in web.config.Add the following setting in your web.config's <appsettings> block.

<appSettings>
        <add key="aspnet:MaxHttpCollectionKeys" value="3000" />
 </appSettings>

You can change the value accordingly as per your need.