SD45 Reskin Pack by Marleyman - Won't Load In Scenarios

I recently downloaded the SD45 Re-skin Package from Marleyman, yet when I go to install an engine in any scenario, it won't load.
I did not have the UP SD45 that was required for the package to work, so I purchased/downloaded it from Steam. Even after doing this, the package still won't load any of the engines in any scenario. They do, however, appear on the list of engines in my RW Train Sim program.
Any suggestions on what I can try to do for this?
Thank you,
Steve
I did not have the UP SD45 that was required for the package to work, so I purchased/downloaded it from Steam. Even after doing this, the package still won't load any of the engines in any scenario. They do, however, appear on the list of engines in my RW Train Sim program.
Any suggestions on what I can try to do for this?
Thank you,
Steve