Factorio Forums

What did you do?
In my 2.0 base I had 500+ trains running that I upgraded in 2.1.9.
A significant portion of the trains seems to get stuck (with stuck I mean, standing still after fully upgrading and not moving despite being able to) and after a bit of investigation I think I may have a reason as to why.

What happened?
The train is parked with the state "DESTINATION_FULL", awaiting a spot.
When using the upgrade planner to change the quality of the train the state changed to "AWAIT_STATION".
It then gets stuck indefinitely and will not move unless a manual intervention.

It seems like only trains with the state "DESTINATION_FULL" are affected, but I can't tell with 100% certainty.

The train will however get unstuck if the condition is met of the NEXT station, making it seem like it thinks it's already parked at the next station.

What did you expect to happen instead? It might be obvious to you, but do it anyway!
For the train to get upgraded and continue functioning as it had before. Most trains that are upgraded will work just fine, a select few get stuck.

Does it happen always, once, or sometimes?
Yes, it seems to work in my big world with every train that is in the state "DESTINATION_FULL"

I created a scenario in which the bug always occurs, it's in the attachments of this post.
Just boot up the save and use the upgrade planner on the bars.
The train on the right will not move.

This bug is still in 2.1.9, despite it's duplicate 134254 reportedly being fixed in 2.1.8.
So sadly, maybe they are not related.

Are you able to reproduce them getting stuck from a working state? There is not a migration to un-stuck existing trains.

In the save game I made to replicate the issue, the train that gets stuck isn't stuck to begin with, only after getting upgraded in a 2.1.9 client.
(Save game in attachments)

It has the state "DESTINATION_FULL" - if the station frees up, it goes as expected.