I was getting this error from last couple of days, This error can occur more  while uploading a large file size . On uploading small size file its show random behavior some time it upload successfully or some time not. The upload progress bar went to 100% in a 2-3 sec when upload a large file size

I also tried to upload on you test upload page I was getting this error

I tried all the solutions from your forum but does not found helpful to me. Please help me out ASAP.