Zumo User Forums

Another way to free up space is to remove all unused languages, vehicles, voices, and jpg files. Save then to your computer in case you want to use them later. If you open windows explorer, you can see where these files are. Make a folder on your computer with the same foler names and copy them ...

I was having the same problem. I found that if i created the route in steps it worked. Create aprt of the route, re-open it and finish.
It does show an extra waypoint (stop) but you can ignore and continue your trip.