When model items like annotations or features were selected, the Creo undo/redo buffer was flushed as a consequence of Creo/Toolkit commands being executed to check whether to perform the active annotation protection. This caused that the Creo buttons for undo and redo were disabled (greyed-out). Due to a software improvement, this behavior was changed in the way, that this buffer won’t be harmed anymore when the user is selecting any model aspects. On the other hand the buffer will still be cleared when the software dialogs are opened and used. This is the general behavior

when Creo/Toolkit manipulates a model/drawing in a Creo session.