title: What system condition could cause "control with id 'xxx' could not be located"?
body: <p>Last night one of our users identified an issue with a site that hasn't had coding changes I'm aware of in 5 months:</p>
  
  <blockquote>
    <p>An error has occurred because a control with id 'xxx' could not be
    located or a different control is assigned to the same ID after
    postback. If the ID is not assigned, explicitly set the ID property of
    controls that raise postback events to avoid this error.</p>
  </blockquote>
  
  <p>I'm wondering what condition could cause this error to occur or if it has to be a code bug? For example low memory, strained CPU, etc.?</p>
  
  <p>The .ascx file referenced does explicitly assign an id.</p>
  
  <p>StackTrace:</p>
  
  <blockquote>
    <p>DotNetNuke.Services.Exceptions.PageLoadException: An error has
    occurred because a control with id
    'dnn$ctr387$Dispatch$Default$rptToDos$ctl00$ctl00' could not be
    located or a different control is assigned to the same ID after
    postback. If the ID is not assigned, explicitly set the ID property of
    controls that raise postback events to avoid this error. --->
    System.Web.HttpException: An error has occurred because a control with
    id 'dnn$ctr387$Dispatch$Default$rptToDos$ctl00$ctl00' could not be
    located or a different control is assigned to the same ID after
    postback. If the ID is not assigned, explicitly set the ID property of
    controls that raise postback events to avoid this error. at
    System.Web.UI.Page.ProcessPostData(NameValueCollection postData,
    Boolean fBeforeLoad) at System.Web.UI.Page.ProcessRequestMain(Boolean
    includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
    --- End of inner exception stack trace ---</p>
  </blockquote>