Unable to start neo4j with systemctl: 'Failed to load from plugin jar' - neo4j

Question

I've been trying to restart neo4j after adding new data on an EC2 instance. I stopped the neo4j instance, then I called systemctl start neo4j, but when I call cypher-shell it says Connection refused, and connection to the browser port doesn't work anymore.
In the beginning I assumed it was a heap space problem, since looking at the debug.log it said there was a memory issue. I adjusted the heap space and cache settings in neo4j.conf as recommended by neo4j-admin memrec, but still neo4j won't start.
Then I assumed it was because my APOC package was outdated. My neo4j version is 3.5.6, but APOC is 3.5.0.3. I download the latest 3.5.0.4 version, but still neo4j won't start.
At last I tried chmod 777 on every file in the data/database and plugin directories and the directories themselves, but still neo4j won't start.
What's strange is when I try neo4j console for all of these attempts, both cypher-shell and the neo4j browser port works just fine. However, obviously I would prefer to be able to launch neo4j with systemctl.
Right now the only hint of error I can find in debug.log is the following:
2019-06-19 21:19:55.508+0000 INFO [o.n.i.d.DiagnosticsManager] Storage summary:
2019-06-19 21:19:55.508+0000 INFO [o.n.i.d.DiagnosticsManager] Total size of store: 3.07 GB
2019-06-19 21:19:55.509+0000 INFO [o.n.i.d.DiagnosticsManager] Total size of mapped files: 3.07 GB
2019-06-19 21:19:55.509+0000 INFO [o.n.i.d.DiagnosticsManager] --- STARTED diagnostics for KernelDiagnostics:StoreFiles
END ---
2019-06-19 21:19:55.509+0000 INFO [o.n.k.a.DatabaseAvailabilityGuard] Fulfilling of requirement 'Database available' mak
es database available.
2019-06-19 21:19:55.509+0000 INFO [o.n.k.a.DatabaseAvailabilityGuard] Database is ready.
2019-06-19 21:19:55.568+0000 INFO [o.n.k.i.DatabaseHealth] Database health set to OK
2019-06-19 21:19:56.198+0000 WARN [o.n.k.i.p.Procedures] Failed to load `apoc.util.s3.S3URLConnection` from plugin jar `
/var/lib/neo4j/plugins/apoc-3.5.0.4-all.jar`: com/amazonaws/ClientConfiguration
2019-06-19 21:19:56.199+0000 WARN [o.n.k.i.p.Procedures] Failed to load `apoc.util.s3.S3Aws` from plugin jar `/var/lib/n
eo4j/plugins/apoc-3.5.0.4-all.jar`: com/amazonaws/auth/AWSCredentials
2019-06-19 21:19:56.200+0000 WARN [o.n.k.i.p.Procedures] Failed to load `apoc.util.s3.S3Aws$1` from plugin jar `/var/lib
/neo4j/plugins/apoc-3.5.0.4-all.jar`: com/amazonaws/services/s3/model/S3ObjectInputStream
2019-06-19 21:19:56.207+0000 WARN [o.n.k.i.p.Procedures] Failed to load `apoc.util.hdfs.HDFSUtils$1` from plugin jar `/v
ar/lib/neo4j/plugins/apoc-3.5.0.4-all.jar`: org/apache/hadoop/fs/FSDataInputStream
2019-06-19 21:19:56.208+0000 WARN [o.n.k.i.p.Procedures] Failed to load `apoc.util.hdfs.HDFSUtils` from plugin jar `/var
/lib/neo4j/plugins/apoc-3.5.0.4-all.jar`: org/apache/hadoop/fs/FSDataOutputStream
...
...
...
2019-06-19 21:20:00.678+0000 INFO [o.n.g.f.GraphDatabaseFacadeFactory] Shutting down database.
2019-06-19 21:20:00.679+0000 INFO [o.n.g.f.GraphDatabaseFacadeFactory] Shutdown started
2019-06-19 21:20:00.679+0000 INFO [o.n.k.a.DatabaseAvailabilityGuard] Database is unavailable.
2019-06-19 21:20:00.684+0000 INFO [o.n.k.i.t.l.c.CheckPointerImpl] Checkpoint triggered by "Database shutdown" # txId: 1
checkpoint started...
2019-06-19 21:20:00.704+0000 INFO [o.n.k.i.t.l.c.CheckPointerImpl] Checkpoint triggered by "Database shutdown" # txId: 1
checkpoint completed in 20ms
2019-06-19 21:20:00.705+0000 INFO [o.n.k.i.t.l.p.LogPruningImpl] No log version pruned, last checkpoint was made in vers
ion 0
2019-06-19 21:20:00.725+0000 INFO [o.n.i.d.DiagnosticsManager] --- STOPPING diagnostics START ---
2019-06-19 21:20:00.725+0000 INFO [o.n.i.d.DiagnosticsManager] --- STOPPING diagnostics END ---
2019-06-19 21:20:00.725+0000 INFO [o.n.g.f.GraphDatabaseFacadeFactory] Shutdown started
2019-06-19 21:20:05.875+0000 INFO [o.n.g.f.m.e.CommunityEditionModule] No locking implementation specified, defaulting
to 'community'
2019-06-19 21:20:06.080+0000 INFO [o.n.g.f.GraphDatabaseFacadeFactory] Creating database.
2019-06-19 21:20:06.154+0000 INFO [o.n.k.a.DatabaseAvailabilityGuard] Requirement `Database available` makes database unavailable.
2019-06-19 21:20:06.156+0000 INFO [o.n.k.a.DatabaseAvailabilityGuard] Database is unavailable.
2019-06-19 21:20:06.183+0000 INFO [o.n.i.d.DiagnosticsManager] --- INITIALIZED diagnostics START ---
I think the warning isn't an issue, since it's just a warning and not an error or exception. Also it seems that the database just shuts down automatically, and then restarts, creating an infinite loop. This loop does not happen when I call neo4j console (all the warnings still exist in the logs). All my ports are default.
Any clue why this is happening? I've never encountered this error when I previously launched neo4j on this instance.

Answer 1

If it works with neo4j console but not with systemctl, you should check the rights of the Neo4j folder.
I'm pretty sure you have a problem on it, and that the systemctl doesn't run Neo4j with the same user as you