Hi,
Please see this post for more details:
http://www.essentialobjects.com/forum/postst4828_AjaxUploader-limiting-upload-file-size.aspxThis usually is caused by a setting that blocks huge request on your server for security reasons. To verify whether the problem is on your server, you can try to upload a file without using our AJAXUploader and see if that goes through. If that does go through, then there is no reason the AJAXUploader will not work. If it does not go through, then you will need to troubleshoot your server.
Thanks!