Free Drive sessions are not always provided by route creators, some route creators provide no sessions at all, just the route. Others create sessions with specific tasks such as take an empty coal train to the mine, load it, take it to the power plant, unload it.
Here is one that I found on the DLS without much effort. It would be suitable for TRS19 Platinum.
<kuid:542976:100168> Free Drive Session
From its screenshot it seems to involve Thomas "stuff" but I am not a fan.
I do not know how Google would be able to find any "symptoms of the problem".
Be warned: Some creators will use assets that have come from 3rd party web sites, i.e. not from the official Trainz DLS and not supplied with your TRS19 install. These creators often will not tell you where to find these "foreign" assets and this will lead to frustrations.
