Hi raynovak,

Does it happens all the time? or randomly?

Please download the latest build http://ajaxuploader.com/download/Ajax-Uploader.zip, it support html5 upload mode, I think it will fix this error for this client. Also, you can let this client install the silverlight plug-in for his browser, it should work too.

This error happens only with flash plug-in and I think you using property "FlashLoadMode". So use HTML5 or Silverlight upload mode will work for him.

Regards,

Ken