Bring Down The Sky installer can't find ME

[eNmelk]

I'm attempting to install Bring Down The Sky for the original Mass Effect. When activating the installer found in this help article, I get an error message saying:

"Mass Effect is not found.

Please reinstall the game from the original source and try again."

The game itself was installed through Origin, and plays fine.

[EA_David]

@eNmelk Hey, do you have the game installed in a non-default location?

It's normally at C:\Program Files (x86)\Origin Games\Mass Effect

[eNmelk]

I did have ME installed on another drive. However, I reinstalled it into the default location and BDtS still won't install.

Would this have anything to do with the fact that I got the serial key from a disk? Is the game a different version based on how you unlock it in Origin?