Same problem on my level 74 Rogue having 14 Hero talents, cannot apply changes as I haven’t “spent all talent points”. GM can do nothing, been a long time now and cannot play the character.
Yeah… I’ve already leveled another rogue to the same level in the time it’s taken to not be fixed. Probably just delete the broken rogue, not an option for other people though I suspect. Poor show this one.
what happens if you try to load a new build, like the starter build etc? or trying to import a set of talents from wowhead etc. what happens if you change spec?
in case its a visual bug try run this in game with talents open, it should click the apply button /run PlayerSpellsFrame.TalentsFrame.ApplyButton:Click()