Say Yes/Oui in each case, s'il vous plait. 

The issue is you have at least one track element in your custom objects (probably a Turnout or a Turntable) that has a track element in it that is "unreachable" via a Path. This was a recent check introduced by Dave, so he can say more, but I think we might want to improve the message to say which object it is... \

One fix would be to delete the object(s) in Manage->Custom Objects, if you dont care about them - otherwise we can take a look at the file in question and see if some surgery would help.

Adam