Welcome @jdavis1980
Upgrade failures are pretty rare, but when they happen, reasons vary from poor SD card contacts, to voltage fluctuations during firmware upgrades. Solutions include cleaning of contacts and re-trying, as well as downgrading to an older version then trying sunlight again. Please have a look at this thread:
Sunlight: Installation and Technical Issues - Audio Components / DACs - PS Audio
I am sure you will resolve this. My best wishes.