gpx cannot load

I am using descent g1 solar. 

I am trying to load a utmb gpx for an 20k trail 

even thou the garmin connect says sync

I use the app and sync

but my watch do not show the route

so online says maybe the route is too complicated for the watch

so from 700 points i used ai to simplify it to 200 points

but the watch still refuse to load

i got a feeling the watch canot do trail run at all with route.