Non existent route: error branch not properly handled: Internal server error, stuck in the page

[pogiaron]

When you try to plan a route between two stations and the route does not exist.
The server responds with 500 Internal Server error.
Then you can not navigate back to the planner with the "Return to the planner" button.

Steps to reproduce.
Plan a route between for example:
Antwerp-Central and Vienna Main Station.
Clikc on the "Return to the planner" button

I attached a video:
screen-capture.webm