When you download event GPS files (each cycle.travel link is on the route page) you should always make sure the file is going to work in your GPS. First, virus-check any downloaded file. Then, know the limitations of your GPS and adapt the file if necessary. If it is a Track and has too many points, it can be split or it can be down-sampled, or both. BikeHike and GPS Visualizer are two online facilities that can make an easy job of down-sampling. If you need a Course then BikeHike or some other planners can convert your file to TCX format.
You may want to add Waypoints or Coursepoints to indicate Control locations if these are not already included.
If you would prefer to use a Route file it’s best to simply use the provided Track for reference and create your own.
Finally, delete all existing Tracks and Routes from your GPS and load the event files in, and use the menus to check that they show on the map and they go all the way to the finish, not stop half way. If you are committed to paperless navigation you should consider carrying a spare GPS in your luggage - just as you would lights, or inner tubes.
Tracking - GPS is not only useful for navigation, but it records your ride as well, and in some circumstances (NB - only by agreement with the Organiser) this may be useful as proof of passage. The default recording settings (on a Garmin) work well and don’t really need to be tweaked for this purpose, and only if the event is a 600km or longer, would you need to make any changes to allow for archiving the complete track log. As far as possible, always submit a 'raw' un-altered, un-tidied track log, straight from the GPS.