I\'m trying to implement a simple ajaxtoolkit fileupload control and every time I click \"Upload\" all I get is an error. I tried placing breakpoint in the \"AjaxFileUpload1
This was happening to me, and I did two things to fix it:
1) Update your site's web.config file to contain entries for the following:
2) If the page you're uploading from is inside a folder with it's own web.config with deny anonymous authorization rules, make sure you add an allow for the AjaxFileUploadHandler like so: