Hey, hope I can help you out. From which version did you jump to which version?
So if I remember correctly, 6.0 was right at the end of the Jade rescue mission?
If that's the case, then old save files are actually incompatible with any version 0.7 and above, as I did major changes on the backend code in that version. Sadly no way to convert old saves into the new data format. There is however a quick start option on 'New Game' that lets you start right into act 3 and the new content.