You should use an appropriate application to open it - try
nano _b2rR6eU9jJ.txt or
cat _b2rR6eU9jJ.txt. The former will edit, the latter will output it to standard output. (Note - you can replace nano with vi, emacs or other text editor of your preference)
From what I can tell
geek@ubuntu:~$ open --help
open: invalid option -- '-'
Usage: openvt [-c vtnumber] [-f] [-l] [-u] [-s] [-v] [-w] -- command_line
open refers to openvt - and the man page describes it as
openvt - start a program on a new virtual terminal (VT). You're trying to open a text file, so unless I'm missing something, it isn't the software for doing what you want to do.