Thanks to you and mcshea98...
I try also to put my paragliding tracks from my GPS Garmin 76S to GE+ without any succes from a few days and I was very happy to find finally your conversation.

So, it is finally a bug in GE+ ! When I think that I bought it only to do that !
I hope they will try to solve the problem.

I have used the way suggested by mcshea98 and it works (see this small track attached) , but it is a little bit complicated for me: I have so many tracks I would like to see with GE !