Phazorx opened the ticket and wrote:

r9712

sending to depot reversed loading train that is longer than station causes:
openttd: /home/ottdcoop/svn-sandbox/src/vehicle.cpp:2936: void Vehicle::LeaveStation(): Assertion `IsTileType(tile, MP_STATION) || type == VEH_SHIP' failed.

logic problem, trainhead after reversing is not on station tile anymore and fails that check.

recommendation: replace "train at station" criteria to either loading or unloading

void Vehicle::LeaveStation()
{
assert(current_order.type == OT_LOADING);
current_order.type = OT_LEAVESTATION;
current_order.flags = 0;
GetStation(this->last_station_visited)->loading_vehicles.remove(this);
}

Reported version: trunk
Operating system: All

This issue was imported from FlySpray: https://bugs.openttd.org/task/747