Netty IO #(increasing number starting from 1) /ERROR Channel became inactive!

The moment the Server started
Netty IO #1/ERROR: Channel became inactive!
was spammed in the console with increasing #'s
(e.g
Netty IO #1/ERROR: Channel became inactive!
Netty IO #2/ERROR: Channel became inactive!
Netty IO #3/ERROR: Channel became inactive!
)

Because it states IO, i'm guessing it has something to do with Input/Output errors?

to reproduce, just start the minecraft server and watch the console