Hello
Frames are available in 9.1, but if I remember only since M060 ...
Have a lokk in User preferences:
WorkgroupManager Client / Workspace Frame Stack Size / Creo
default is 0, so frames are disable. put the value you want to be able to "undo"
Once set, in your Workspace, in the action menu / Event management.
You will be able to click on last saved objects and go back to a previsous state ...
regards