Had this happen twice now: I refund my traits while in Heart of the Mists and then go to assign them but cannot – when you click on the traits the selection popup does not show up. You can hit the + button and fill up the points but still cannot select traits.
Logging out and back in clears the problem up… so “low” priority unless it’s low-hanging fruit!!!
PS – the first occurrence was LAST night prior to the update today – the second one was just now. So not specific to latest build.