Mongo no longer connects

I am getting a same error. deleted /tmp/mongodb-27017.sock file. getting following error:

mongod
2019-10-23T08:50:08.484-0400 I CONTROL  [initandlisten] MongoDB starting : pid=2756 port=27017 dbpath=/data/db 64-bit host=AEC-logs-mongodb-512mb-nyc3-01
2019-10-23T08:50:08.484-0400 I CONTROL  [initandlisten] db version v3.2.19
2019-10-23T08:50:08.484-0400 I CONTROL  [initandlisten] git version: a9f574de6a566a58b24d126b44a56718d181e989
2019-10-23T08:50:08.485-0400 I CONTROL  [initandlisten] OpenSSL version: OpenSSL 1.0.1f 6 Jan 2014
2019-10-23T08:50:08.485-0400 I CONTROL  [initandlisten] allocator: tcmalloc
2019-10-23T08:50:08.485-0400 I CONTROL  [initandlisten] modules: none
2019-10-23T08:50:08.485-0400 I CONTROL  [initandlisten] build environment:
2019-10-23T08:50:08.485-0400 I CONTROL  [initandlisten]     distmod: ubuntu1404
2019-10-23T08:50:08.485-0400 I CONTROL  [initandlisten]     distarch: x86_64
2019-10-23T08:50:08.485-0400 I CONTROL  [initandlisten]     target_arch: x86_64
2019-10-23T08:50:08.485-0400 I CONTROL  [initandlisten] options: {}
2019-10-23T08:50:08.511-0400 I -        [initandlisten] Detected data files in /data/db created by the 'wiredTiger' storage engine, so setting the active storage engine to 'wiredTiger'.
2019-10-23T08:50:08.512-0400 W -        [initandlisten] Detected unclean shutdown - /data/db/mongod.lock is not empty.
2019-10-23T08:50:08.512-0400 W STORAGE  [initandlisten] Recovering data from the last clean checkpoint.
2019-10-23T08:50:08.512-0400 I STORAGE  [initandlisten] wiredtiger_open config: create,cache_size=1G,session_max=20000,eviction=(threads_min=4,threads_max=4),config_base=false,statistics=(fast),log=(enabled=true,archive=true,path=journal,compressor=snappy),file_manager=(close_idle_time=100000),checkpoint=(wait=60,log_size=2GB),statistics_log=(wait=0),verbose=(recovery_progress),
2019-10-23T08:50:08.566-0400 I STORAGE  [initandlisten] dropping unused ident: index-0-3415813987516495599
2019-10-23T08:50:08.567-0400 I STORAGE  [initandlisten] dropping unused ident: index-1-3415813987516495599
2019-10-23T08:50:08.567-0400 I STORAGE  [initandlisten] dropping unused ident: index-2-3415813987516495599
2019-10-23T08:50:08.568-0400 I STORAGE  [initandlisten] dropping unused ident: index-3-3415813987516495599
2019-10-23T08:50:08.568-0400 I STORAGE  [initandlisten] dropping unused ident: index-4-3415813987516495599
2019-10-23T08:50:08.569-0400 I STORAGE  [initandlisten] dropping unused ident: index-5-3415813987516495599
2019-10-23T08:50:08.570-0400 I STORAGE  [initandlisten] dropping unused ident: index-6-3415813987516495599
2019-10-23T08:50:08.571-0400 I CONTROL  [initandlisten] ** WARNING: You are running this process as the root user, which is not recommended.
2019-10-23T08:50:08.571-0400 I CONTROL  [initandlisten] 
2019-10-23T08:50:08.571-0400 I -        [initandlisten] Fatal assertion 28579 UnsupportedFormat: Unable to find metadata for table:index-1--4778676036905453176 Index: {name: _id_, ns: local.customers} - version too new for this mongod. See http://dochub.mongodb.org/core/3.4-index-downgrade for detailed instructions on how to handle this error.
2019-10-23T08:50:08.572-0400 I -        [initandlisten] 

Thank you @hansen. I don’t have a mongodb.log but I do have mongod.log:

2017-06-23T01:48:28.663-0400 I CONTROL  [initandlisten]     distmod: ubuntu1604
2017-06-23T01:48:28.663-0400 I CONTROL  [initandlisten]     distarch: x86_64
2017-06-23T01:48:28.663-0400 I CONTROL  [initandlisten]     target_arch: x86_64
2017-06-23T01:48:28.663-0400 I CONTROL  [initandlisten] options: { config: "/etc/mongod.conf", net: { bindIp: "127.0.0.1", port: 27017 }, storage: { dbPath: "/var/lib/mongodb", journal: { enabled: true } }, systemLog: { destination: "file", logAppend: true, path: "/var/log/mongodb/mongod.log", quiet: true } }
2017-06-23T01:48:28.720-0400 E NETWORK  [initandlisten] Failed to unlink socket file /tmp/mongodb-27017.sock errno:1 Operation not permitted
2017-06-23T01:48:28.720-0400 I -        [initandlisten] Fatal Assertion 28578
2017-06-23T01:48:28.720-0400 I -        [initandlisten] 

***aborting after fassert() failure


2017-06-23T01:56:30.912-0400 I CONTROL  [main] ***** SERVER RESTARTED *****
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten] MongoDB starting : pid=19105 port=27017 dbpath=/var/lib/mongodb 64-bit host=currency
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten] db version v3.2.12
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten] git version: ef3e1bc78e997f0d9f22f45aeb1d8e3b6ac14a14
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten] OpenSSL version: OpenSSL 1.0.2g  1 Mar 2016
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten] allocator: tcmalloc
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten] modules: none
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten] build environment:
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten]     distmod: ubuntu1604
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten]     distarch: x86_64
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten]     target_arch: x86_64
2017-06-23T01:56:30.930-0400 I CONTROL  [initandlisten] options: { config: "/etc/mongod.conf", net: { bindIp: "127.0.0.1", port: 27017 }, storage: { dbPath: "/var/lib/mongodb", journal: { enabled: true } }, systemLog: { destination: "file", logAppend: true, path: "/var/log/mongodb/mongod.log", quiet: true } }
2017-06-23T01:56:30.976-0400 E NETWORK  [initandlisten] Failed to unlink socket file /tmp/mongodb-27017.sock errno:1 Operation not permitted
2017-06-23T01:56:30.976-0400 I -        [initandlisten] Fatal Assertion 28578
2017-06-23T01:56:30.976-0400 I -        [initandlisten] 

***aborting after fassert() failure