Following an upgrade of DotNetNuke from 05.02.02 to 05.06.06 we now get the following error in all browsers when posting back on a module where partial rendering is enabled.

Sys.InvalidOperationException: A control is already associated with the element.

This error occurs on all modules even standard ones, e.g. File Manager (assuming we change the File Manager to partial rendering). This occurs even when using the standard Skin. In order to confirm this wasn't an isolated incident we've upgrade three separate sites from 05.02.02 to 05.06.06 and all sites exhibit the same problem. All our current sites exclusively currently use 05.02.02 so we are eager to start to upgrade these but can't until we resolve this issue. 

If I install 05.06.06 from scratch then all is well so the problem is related to the upgrade. I've checked the web.config on the (working) new install and the non-working upgrade and they are pretty much the same (other than db connection info etc.) so I don't think this is the problem. 

The code which errors on the upgraded sites is the following bolded/underlined text below:

Sys.UI.Control = function Sys$UI$Control(element) {
    /// <summary locid="M:J#Sys.UI.Control.#ctor" />
    /// <param name="element" domElement="true"></param>
    var e = Function._validateParams(arguments, [
        {name: "element", domElement: true}
    ]);
    if (e) throw e;
    if (typeof(element.control) != 'undefined') throw Error.invalidOperation(Sys.Res.controlAlreadyDefined);
    Sys.UI.Control.initializeBase(this);
    this._element = element;
    element.control = this;
}

The element variables which error are the following. If there are no HTML modules, then only the first one errors.

"dnn_ctr370_dnnACTIONS_ctldnnACTIONS"
"dnn_ctr487_HtmlModule_lblContent"

Incidentally there was an additional error for "dnn_dnnNAV_ctldnnNAV", but I managed to get rid of this by changing the menu provider in the skin from DNNMenuNavigationProvider to DDRMenuNavigationProvider. However, making the same change for the action menu in the containers did not get rid of the dnnACTIONS error above.

Any help on this will be gratefully received as this is preventing us upgrading our sites currently.

(Please don't ask why we're not directly upgrading to DNN 6! The reason is problems with the Ajax Control Toolkit which I'm going to add an other post on).

I am having the same issue. Were you able to resolve this or did you hear back from the DNN team?

Thanks for posting this Karl. I too have spent countless hours trying to determine if it was related to code I've written, but came to the same conclusion you did.

Given the huge performance problems we've seen with dnn 6, staying with v5 was our best choice, but these errors are causing my customers to look elsewhere, which is very discouraging. Hopefully, this problem will be addressed asap...

We also noticed that these errors were occuring when writing settings modules as well, regardless of the partial rendering setting for the control definition.