What is a TCP Connection Reset by Peer?

An application gets a connection reset by peer error when it has an established TCP connection with a peer across the network, and that peer unexpectedly closes the connection on the far end. That usually happens when the peer crashes, but can also happen with poorly-written applications or frameworks that don't shut their TCP connections down cleanly. Similar to a connection refused error, a connection reset by peer error is generated when the operating system receives a TCP reset (RST) from the remote system.