When one try to perform a replace from a steam locomotive to an electric locomotive, it head to a nearby depot that may be compatible, but do not care if the depot is electrified. Therefore, an electric locomotive is purchased in a non-electrified depot and stays in the depot without restarting. But no warning message is given about it.
This saved game (https://drive.google.com/open?id=15OeaefKdLrXtVp-iv9Y98ond2XVuWEvn) is about to be replaced with an electric locomotive in a non-electrified depot.
I do not think there is a problem with this depot arrangement. Diesel train can only be purchased in that depot. Therefore it may be in a non-electrified location.
It is quite possible that there is a diesel depot nearby by chance when replacing vehicles on the line.
The problem is to check for a convoy compatible depot after replacement, but do not care if it is electrified and the axle load is within the allowable range. I think at least the former has a problem.
Vehicles with axle load that cannot be purchased in the depot can also be purchased(replace) in this way.