Thanks for this suggestion.
In fact, the upgrade to Yosemite has been done automatically, so I suppose the location of folders was normal. I verified and it seems to me that it is OK.
But as I saw in other discussions that iDVD is abandoned since 2 years, I tried to find another method, and I found this:
- Directly into "Photos"
- Select all photos of the album
- "Fichier / Créer diaporama..." and it is possible to EXPORT it (on finder for instance):
- So we can open it and it runs automatically with VLC
- And It is possible also to put it on a DVD, with music and regulation of duration!...
I apologize for my bad english language...