i highlight some photos and then right-click on the map
select 'add selected photos..'
if i restart LR it might work once or twice then quit
sometimes i can't even highlight the 'add...' button
upgraded to win10 (from 8.1) 2 weeks ago
LR CC 2015 up-to-date
Sounds just like my issue. Seems like LR looses the selection just before starting the task. Did you ever get a response or figure it out?
no, still broken