upon startup, I am receiving this error.
JanusGraphException: Could not execute operation due to backend exception (AtlasJanusGraphDatabase:110)
Atlas uses HBase as the back-end database can you ensure HBase is running. If you don't have production metadata you could as well reset or wipe-out metadata store of Atlas using Ayub khan's document after wiping and dropping atlas_titan and ATLAS_ENTITY_AUDIT_EVENTS when you restart Atlas these 2 tables will be recreated.
However, make sure Atlas is stopped when performing the above.