I get this error when migrating my database and upgrading to 1.9.3:
"Property 'databaseSchema' needs to be specified in the configuration

I have this in my keycloak-server.json file:

"connectionsMongo": {
        "default": {
            "host": "xx.xx.xx.xx",
            "port": "27017",
            "db": "keycloaktest",
            "databaseSchema": "update"
        }
    }