Issue description
Clicking unstuck and return to depot button works however if the train is out of fuel it will appear in depot then try to leave but will not refuel even if fuel is available in depot. Because train is departing depot it doesn't give warning message about an idle train nor does it display train in depot screen. As it's out of fuel it will appear on track in depot but will not move. Technically train is on track in depot but not displayed in depot screen and as it's out of fuel it won't move.
This causes all other trains in depot to not leave depot, as there is another train in the way, but it's not obvious what the issue is. Only by careful observation of seeing a train in exit of depot can one see the unfueled train and refuel it. Even unbuilding and rebuilding does not solve problem as individual car and locomotive states are saved, including the out of fuel condition. Only by clicking on stuck train in depot and refueling it can the issue be corrected.
Reproduction steps
Make a valid train network and depot, train stops and train schedule.
Build two trains of any car length or type to add to schedule.
Immediately return and pause one train, so it still has fuel but is in depot and on schedule
Run other train until it runs out of fuel.
Return out of fuel train to depot with unity button
unpause the out of fuel train in depot screen
Train that is out of fuel will immediately appear on track in depot but will not leave as it has no fuel, can see locomotive in exit gate.
Unpause train with fuel in depot
Train with fuel will not leave depot as it's stuck behind the unfueled train.
No error or warning message will show about idle trains out of fuel or otherwise indicate what the problem is.
Only by clicking on out of fuel locomotive in depot and refueling it can the issue be solved.
The problem is it's not obvious what the issue is and requires one to observe the locomotive stuck in the depot and clicking on the stuck and well hidden train and refueling it.
Game version and build number
v0.7.5
Operating system
Windows
