Invalid postback or callback argument

I keep seeing these errors in my website error log every once in a while:

Error Message:
Invalid postback or callback argument. Event validation
is enabled using 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.Error
Source:
System.Web
Error
Data:
System.Collections.ListDictionaryInternal

Error Stack
Trace:
at System.Web.UI.ClientScriptManager.ValidateEvent(String
uniqueId, String argument) at System.Web.UI.Control.ValidateEvent(String
uniqueID, String eventArgument) at
System.Web.UI.WebControls.HiddenField.LoadPostData(String p ...