The moon jellyfish genome browser is currently undergoing maintenance as it moves to a new server.
Until then, the raw data (including the genome) can be downloaded at NCBI under BioProject PRJNA490213.
I am also making the data behind the genome browser accessible through this link. This currently includes:
- The genome (in FASTA format)
- Gene models (in GFF3 format)
- Repeat models (in GFF3 format)