I haven't been able to upload course files for the last week. I've successfully uploaded courses many times in the past. Is anybody else having this problem?
On RideWithGPS there are several GPX options and you must be careful what you do. The default works with the Edge. But some options remove the track from the file and are not usable by the Edge. I am quite sure if you tick the one with turn announcements it won't work. You leave this out, the Edge will compute it's own if you enable Turn-by-Turn navigation on the Edge.
FIT, TCX, and GPX (track*) all work the same for turn guidance (the big white arrows).
They all contain the same information.
These files (these are all track files) have a list of points that trace the curves and turns of the path you plan to follow. The Garmins calculate the turn guidance by walking the track and matching it up to the nearest road.
The units convert TCX and GPX to FIT.
FIT and TCX can contain "course points", which pop-up as text with a black background. This is a separate (parallel) navigation mode. It was originally intended for devices that didn't have maps.
Your unit appears to be seeing the gpx format as invalid. This isn't a general problem because we'd likely be hearing a lot about it.
If the other formats work, use them instead.
* The non-track GPX options won't work. If you are using GPX on the Edges, you must use GPX track.
My point was that if you read carefully the options when generating GPX and TCX on the RideWithGPS site, under export, some options generate a file with clue sheets but NO track information. The XML is then a simple list of waypoints with no route or track in it. I am not making this up, it is clearly stated. (click Export and then Other Formats to see all the options). The one without the track they call it GPX Route if I am not mistaken while the other is called GPX Track. Totally confusing but hey that's the way it is.