Commented Issue: AjaxFileUpload assumes no query strings already exist in page URL on postback [27149]

When AjaxFileUpload post back it takes your page URL and appends onto the end of it it's own query strings (contextkey and guid). This works fine if your page URL doesn't already contain any query strings but if it does then you end up with a URL that contains two question marks which then corrupts your own final query string value and this in turn stops the upload from working.
Comments: irecord is correct AjaxFileUpload.pre.js - line 375 uploader._vForm.action = uploader._postBackUrl + '?contextkey=' + this._contextKey + '&guid=' + this._guid; changed to uploader._vForm.action = uploader._postBackUrl + '&contextkey=' + this._contextKey + '&guid=' + this._guid; AjaxFileUpload.pre.js - line 176 this._webRequest.set_url(this._postBackUrl + '?contextkey=' + this._contextKey + '&guid=' + this._guid); changed to this._webRequest.set_url(this._postBackUrl + '&contextkey=' + this._contextKey + '&guid=' + this._guid); I compiled, copied the AjaxControlToolkit.dll to the bin folder in my project. worked like a charm. someone with more time can add the logic irecord mentioned, but I only plan on using the upload with something in the querystring. i attached my file if anybody is interested.