Ok, don't worry about the prefix table. As I said, it has nothing to do with awards tracking. You could delete every record in it and still track awards -- you would just have to log every country, zone etc manually.
Anyway, it looks like something deleted the South Sudan record. Please just add it back. Or import the attached DXCC list (Save DXCC.DBF some somewhere -- anywhere you can find it, not in the LOGic folder. Then use the IMPORT LIST button on the Lists of Valid Values screen). Do awards/update awards progress info. If that doesn't take care of it I can log into your machine and check it out.
We never put South Sudan in an official tables update because it came live long before the ARRL assigned a number and their govt assigned an official prefix. So people added it themselves using whatever and it needed changing afterwards.
Tnx & 73,
Dennis WN4AZY