been trying to install this indicator and I keep
getting this error, I don't have duplicate files and I'm
using ninjatrader 8.1.1, it's the ninjatrader journal link
from TradesViz. Can anyone help with this?

hi the last version of ninjatrader you are using has to be fixed for some bugs

uninstall it and install the last but one version (you can download this version from the ninjatrader website