NOTE:  Serial error reporting is sent to the hardware serial port for viewing with the serial port monitor - errors messages are not sent to serial2.

The ESP-8266  devices use GPIO1 for TX and GPIO3 for RX -  Chapter 4 - TX RX Hack shows how to make alternative use of those gpio's.

The hardware serial and software serial2 ports both have similar usage instructions, as demonstrated in the Dual Serial Portal Bridge  project.