Currently, copying or renaming the SFA file or folder breaks the link with STAAD.Pro and cannot be restored. This is problematic for users wishing to explore multiple design options. It is fairly common practice to make a backup of your work and proceed with alternative designs. The expectation being that you should always be able to come back to or restore your previous work.
Please include improved flexibility to rename the working folder and/or SFA file and later re-establish the link between STAAD.Pro and said SFA file.