I did a mongodb 4.2.1 fresh install on my digital occean ubuntu 18.04 LTS droplet. For some weird reason the service daemon does not start.
019-12-05T11:35:31.148+0000 I CONTROL [main] ***** SERVER RESTARTED ***** 2019-12-05T11:35:31.153+0000 I CONTROL [main] Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none' 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] MongoDB starting : pid=1291 port=27017 dbpath=/var/lib/mongodb 64-bit host=ubuntu-s-1vcpu-2gb-blr1-01 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] db version v4.2.1 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] git version: edf6d45851c0b9ee15548f0f847df141764a317e 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] OpenSSL version: OpenSSL 1.1.1 11 Sep 2018 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] allocator: tcmalloc 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] modules: none 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] build environment: 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] distmod: ubuntu1804 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] distarch: x86_64 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] target_arch: x86_64 2019-12-05T11:35:31.167+0000 I CONTROL [initandlisten] options: { config: "/etc/mongod.conf", net: { bindIp: "0.0.0.0", port: 27017 }, processManagement: { timeZoneInfo: "/usr/share/zoneinfo" }, storage: $ 2019-12-05T11:35:31.169+0000 E STORAGE [initandlisten] Unable to read the storage engine metadata file: FileNotOpen: Failed to read metadata from /var/lib/mongodb/storage.bson 2019-12-05T11:35:31.169+0000 F - [initandlisten] Fatal Assertion 28661 at src/mongo/db/storage/storage_engine_metadata.cpp 89 2019-12-05T11:35:31.169+0000 F - [initandlisten] 
3.6version it works. Don't know what breaks for ` 4.2.1`