Factorio Forums

1. What did you do?
Placed a parameterised blueprint that assigned a sulphuric acid group to a train, along with a parameterised configuration
2. What happened?
The train had no configuration, and was assigned to group "[Suplhuric Acid] delivery" as the third train of that group, despite no other trains in that group physically existing. Checking the Trains menu reveals no such group before the blueprint is placed, and after placement, it shows a single train in that group. A train in this group does not exist on another planet.
3. What did you expect to happen instead? It might be obvious to you, but do it anyway!
For the train to create a new group, and to come with the blueprint's configuration.
4. Does it happen always, once, or sometimes?
Always, for sulphuric acid. Selecting different fluids results in intended behaviour.

Attached entire save file as I imagine there might be some phantom train somewhere with an empty config, or something like that.

Ah, figured it out, apologies.
There were two locomotive-lacking cargo wagons that were storing the group on them, along with the empty configuration. Destroying them completely wiped them from the group.
I understand why train data is stored in locomotive-less trains, however perhaps it should still appear on the train list in groups, with some clarification that it lacks a locomotive.

I came to report this bug, and searched first, and was suprised to find this in "Not a bug".

When there's a cargo car that is causing a Train Group schedule to continue to exist, there's no way to determine that. It doesn't show up in the Train Groups list. And if you put down a new locomotive in that Train Group, it shows (e.g.) "[2]" trains in the group, even though you've just put down only one. And again, if you go to the Train Groups list, it only shows the one newly-placed locomotive.

The UI is inconsistent and the overall behavior here is non-intuitive. Seems like a bug.