There was no match between the visible catenary and the internal catenary. This is no misuse of the Map Editor, it may be a bug.
You have to open the property window of the catenary element next to the hidden catenary. Then click "OK" to invoke the refresh of the Map Editor. After saving the catenary should work in the simulator when testing. If the catenary is NOT working, error may set within a catenary element nearby. The method to refresh the catenaries remains the same as described before.