Logged in to see I had 16 legacy talents. I put them in the nodes I want, hit apply changes and it tells me “unable to learn talents”. I have tried restarting game, my PC, switching characters and yet it says the same on every one.
EDIT: all my guildies did them just fine.
probably a bug 
having the same issue
I had the same issue after resetting the points i’d already assigned with that crossed out circle red icon on the legacy points menu. i had to undo pending changes, then assign the new points (leaving the ones that were already spent) before it let me save those changes