I’ve installed couchbase-server-community-4.0.0-centos7.x86_64.rpm and couchbase-sync-gateway-community_1.2.0-79_x86_64.rpm on a red hat enterprise edition 7.2. Differently from your configuration i’ve used “5minxte” also as “databases” key.
As soon as possible I’ll retry to use the old name to verify where the problem effectively was.
Thanks for your reply!