When I try to run packetforge in BT3 I get the message "cannot execute binary file"

Even if I try packetforge-ng /? I still get the message. Have I done something wrong? The entire string reads:

-bash: /usr/local/bin/packetforge-ng: cannot execute binary file

When I browse /usr/local/bin, packetforge-ng is a text file, not an executable

Thanks