I have the same problem.
Here is my Mac. I've got the iTunes 12.2.2 and can't install a higher version, however, my mac seems to have all the requirements.
I'm not able to connect with ImageTransfert too...
Nom du modèle: Mac Pro
Identifiant du modèle: MacPro1,1
Nom du processeur: Dual-Core Intel Xeon
Vitesse du processeur: 2,66 GHz
Nombre de processeurs: 2
Nombre total de cœurs: 4
Cache de niveau 2 (par processeur): 4 Mo
Mémoire: 3 Go
Vitesse du bus: 1,33 GHz
I suppose the next advise would buy a new Mac ?
But this one works perfectly...
Is it possible to downgrade to the previous IOS ? Morevoer, this version brings plenty of useless gadgets and no real fonctionnality.