Not an expert here (correct me if I’m wrong someone) and I don’t yet own the 185, but ATS products generally just download an installer (hence the small file size), which then runs an exe file that downloads and installs the DLC. It may be that your anti virus program is blocking this – Avast does this for me and I have to temporarily disable it every time – it could be worth a try.
One stop shop for Train Simulator downloadable content, routes, scenarios, reskins, patches mods and user generated free, subscription and payware Train Sim addons.
