I was having difficulties connecting to my LPC-Link2 through MCUXpresso. It all of a sudden quit being able to connect to the redlink server. The IDE was saying the server was closed, but I could see it was running in Windows Task Manager.
Our target MCU hosts an embedded web server. One of the ethernet connectors on my PC was connected to the internet, and the other was connected to the target MCU's ethernet port.
I unplugged the ethernet connector to the target MCU, hit debug, and it immediately began working again. I was struggling to figure out why I couldn't connect, and looked through various forum posts for similar issues.
If you are experiencing a similar error then try unplugging your ethernet connection as another option.