Steps to prevent previously filled values being lost when signed off by a client, or the inability to setup as a LiveForm due to encryption.
1 - Download the original file using the Download button (or access your original copy)
2 - Open the file using chrome (You can do this by right-clicking the file and using Open With...)
3 - Click the Print button (Top right corner)
4 - Set the 'Destination' dropdown menu to Save as PDF and then save the document.
** You can now set up the form as a Live Form without any fields being wiped! **