Hope that DTG can do a update/patch so all routes/dlc works in 64-bit. As I said in another thread the Chessie System U30C Loco Add-On does not work in 64-bit. https://store.steampowered.com/app/376958/Train_Simulator_Chessie_System_U30C_Loco_AddOn/
As the U30C is a third-party product, it would be up to the developer to sort out compatibility. Unfortunately, VRC closed up shop a little less than a year ago, so this is a problem that will remain unfixed.
