Boost::Asio Server reads blank message from client, even after the write handle finis

I try to write an async message to the server from my client code, the write handler gets called with the correct bytes sent; however, the server receives 0 bytes.

Cliente output:

Code:

You are connected You received the following message from the server: Sat Aug 20 17:42:01 2016 Sending...

Server output:

Code:

Server is online! 127.0.0.1:51973 connected! Client has received the messaged. You received the following message from the server:

server source: http://pastebin.com/h9ty5N9w

client source: http://pastebin.com/yv2z4na0