Another lingering library bug after SR2, at least on P8 Mac.... Sometimes, but not in any way I can reliably reproduce, the + sign disappears from the library. That is, I will be in a Props folder and have a prop selected in my scene, but cannot add it to the library because the + button is gone. Sometimes going out of the folder and back in again will restore it, other times that does not work and P8 must be relaunched.

This is not directly tied to the bugs mentioned above (Undo failing or menu commands being grayed out) because it does not happen at the same time. Bagginsbill could elaborate, but I don't think library bugs such as this are related to general memory bugs.