Getting "Cannot access a closed file" errormessage when getting file from session

I have a asp.net FileUpload control. I can successfully upload file to store in session, but when I am tring to get its inputstream (I'm store file in HttpPosterFile) I'm getting error

Cannot access a closed file

tr.PostedFile //<== HttpPostedFile; 
byte[] byteArray = null; 
using (var binaryReader = new BinaryReader(tr.PostedFile.InputStream)) 
{ 
    byteArray = binaryReader.ReadBytes(tr.PostedFile.ContentLength); 
}