Internet Explorer 7 & 8 issue with Prototype 1.6.1 - Could not complete the operation due to error c00ce56e.

Question

I'm at a loss. I found a few things that mentioned IE needed to have the response type specified and I changed that to text/html and that did nothing for me.

There Error:

Could not complete the operation due to error c00ce56e. prototype.js, line 1564

Points to in prototype.js:

if((readyState > 2 && !Prototype.Browser.IE) || readyState == 4) {
  this.status       = this.getStatus();
  this.statusText   = this.getStatusText();
  this.responseText = String.interpret(transport.responseText); <!--- ERROR is here --->
  this.headerJSON   = this._getHeaderJSON();
}

The function called from an onClick() in an href:

function f(op, cl) {
    if(op && cl) {
            new Ajax.Updater('favorites-' + cl, '/fav.php',
            {
                    onComplete: function(transport) {
                            if(transport.responseText == 1 && cl) $('favorites-' + cl).remove();
                            else return transport.responseText;
                            },
                    onException: function(r, e) {
                                    alert('Updater ' + e);
                            },
                    method: 'get',
                    parameters: { cl: cl, op: op },
                    encoding: 'UTF-8',
                    contentType: 'text/html'
            });
    }
}

Answer 1

Error C00CE56E typically happens when your script returns an encoding (by Content-Type charset parameter or <?xml encoding) that IE doesn't recognise, for example if you say ‘utf8’ instead of the correct ‘utf-8’. This has to be fixed at the server-side.

What is the Content-Type header your server is sending?