if the problem isn't on your application but on server application and you you're trying to access an webApplication via WCF, you need to set the maxRequestLength on server application like the same action made on app.config.
http://msdn.microsoft.com/pt-br/library/e1f13641(v=vs.85).aspx
If the exception throws on you WCF application, you need to set the maxReceivedMessageSize on app.config.
WCF by default limits messages to 64KB to avoid DOS attack with large message. By default, it sends byte[] as base64 encoded string and it increases the size of the message (33% increase in size). There for if the uploaded file size is ~larger than 48KB then it raises the above error. (48KB * 1.33 = ~64KB) (NB. you can use MTOM – Message Transmission Optimization Mechanize to optimize the message)
By modifying the "maxReceivedMessageSize" in the Web.config file to accept large messages, you can solve this issue.
(413) Request Entity Too Large[
^]
Best regards,
Leonardo Metre