# Problem with installing APOC in neo4j server **URL:** \ **Category:** Installation\ **Tags:** apoc\ **Created:** [January 10, 2022, 6:50am UTC](https://community.neo4j.com/t/problem-with-installing-apoc-in-neo4j-server/50232 "2022-01-10T06:50:56Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![joannelyu](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/joannelyu/32/21710_2.png) [@joannelyu](https://community.neo4j.com/u/joannelyu)\ **Post date:** [January 10, 2022, 6:50am UTC](https://community.neo4j.com/t/problem-with-installing-apoc-in-neo4j-server/50232/1 "2022-01-10T06:50:56Z")
Hello, My apoc plugin is not correctly installed, but I really don't know what went wrong. - OS: CentOS 7 - neo4j version: 4.4.1 - API / driver: Neo4j GraphQL Library Jar file under plugins folder: `/var/lib/neo4j/plugins/` `-rwxr-xr-x 1 neo4j neo4j 23302562 Dec 9 19:06 apoc-4.4.0.1-all.jar` In config file: `/etc/neo4j/neo4j.conf` ```auto dbms.security.procedures.unrestricted=apoc.* dbms.security.procedures.allowlist=apoc.coll.*,apoc.load.*,apoc.* apoc.import.file.enabled=true ``` When I run: ```auto neo4j@neo4j> call apoc.help("help"); Failed to invoke procedure `apoc.help`: Caused by: java.lang.ClassNotFoundException: org.neo4j.graphdb.TransactionGuardException ``` When I call some Neo4j GraphQL APIs, I get: `Unhandled Rejection (Error): Unknown function 'apoc.util.validatePredicate'` Neo4j has been restarted many times. Please help, Thanks! Regards, Joanne ---
**Author:** ![giuseppe\_villan](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/giuseppe_villan/32/11871_2.png) [@giuseppe\_villan](https://community.neo4j.com/u/giuseppe_villan)\ **Post date:** [January 10, 2022, 11:34am UTC](https://community.neo4j.com/t/problem-with-installing-apoc-in-neo4j-server/50232/2 "2022-01-10T11:34:56Z")
@joannelyu There is something useful in `neo4j.log` and `debug.log` files? The config seems correct (anyway, in `dbms.security.procedures.allowlist` you can write only `apoc.*`, but the result is the same) ---
**Author:** ![joannelyu](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/joannelyu/32/21710_2.png) [@joannelyu](https://community.neo4j.com/u/joannelyu)\ **Post date:** [January 11, 2022, 1:49am UTC](https://community.neo4j.com/t/problem-with-installing-apoc-in-neo4j-server/50232/3 "2022-01-11T01:49:35Z")
Dear @giuseppe_villan Here is some part of the log: ```auto 2022-01-11 01:28:22.426+0000 INFO [o.n.d.i.DefaultIdentityModule] Found ServerId on disk: ServerId{7f148f53} (7f148f53-aa87-40d2-883d-8696dfb3c052) 2022-01-11 01:28:22.427+0000 INFO [o.n.d.i.DefaultIdentityModule] This instance is ServerId{7f148f53} (7f148f53-aa87-40d2-883d-8696dfb3c052) 2022-01-11 01:28:22.431+0000 INFO [o.n.g.f.EditionLocksFactories] Locking implementation 'forseti' selected. 2022-01-11 01:28:24.512+0000 INFO [o.n.s.CommunityNeoWebServer] ======== Neo4j 4.4.1 ======== 2022-01-11 01:28:24.544+0000 INFO [o.n.d.d.DefaultDatabaseManager] Creating 'DatabaseId{00000000[system]}'. 2022-01-11 01:28:24.639+0000 INFO [a.ApocConfig] successfully registered ApocConfig for @Context 2022-01-11 01:28:24.641+0000 INFO [a.Pools] successfully registered Pools for @Context 2022-01-11 01:28:24.674+0000 INFO [a.ApocConfig] from system properties: NEO4J_CONF=/etc/neo4j 2022-01-11 01:28:24.674+0000 INFO [a.ApocConfig] system property NEO4J_CONF set to /etc/neo4j 2022-01-11 01:28:24.674+0000 INFO [a.ApocConfig] loading apoc meta config from jar:file:/var/lib/neo4j/plugins/apoc-4.4.0.1-all.jar!/apoc-config.xml 2022-01-11 01:28:25.076+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.jobs.pool.num_threads=null 2022-01-11 01:28:25.076+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.export.file.enabled=false 2022-01-11 01:28:25.077+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.ttl.enabled=false 2022-01-11 01:28:25.077+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.ttl.schedule=PT1M 2022-01-11 01:28:25.078+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.jobs.queue.size=null 2022-01-11 01:28:25.078+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.initializer.cypher=null 2022-01-11 01:28:25.078+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.jobs.scheduled.num_threads=null 2022-01-11 01:28:25.079+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.import.file.enabled=true 2022-01-11 01:28:25.080+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.trigger.enabled=false 2022-01-11 01:28:25.080+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.import.file.use_neo4j_config=true 2022-01-11 01:28:25.081+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.uuid.enabled=false 2022-01-11 01:28:25.082+0000 INFO [a.ApocConfig] setting from neo4j.conf: apoc.ttl.limit=1000 2022-01-11 01:28:25.166+0000 INFO [o.n.b.BoltServer] Bolt server loaded 2022-01-11 01:28:25.313+0000 ERROR [o.n.g.f.DatabaseManagementServiceFactory] Error starting Neo4j database server at /var/lib/neo4j/data/databases org.neo4j.kernel.lifecycle.LifecycleException: Component 'org.neo4j.kernel.internal.locker.LockerLifecycleAdapter@15515c51' was successfully initialized, but failed to start. Please see the attached cause exception "Lock file has been locked by another process: /var/lib/neo4j/data/databases/store_lock. Please ensure no other process is using this database, and that the directory is writable (required even for read-only access)". at org.neo4j.kernel.lifecycle.LifeSupport$LifecycleInstance.start(LifeSupport.java:463) ~[neo4j-common-4.4.1.jar:4.4.1] at org.neo4j.kernel.lifecycle.LifeSupport.start(LifeSupport.java:110) ~[neo4j-common-4.4.1.jar:4.4.1] at org.neo4j.graphdb.facade.DatabaseManagementServiceFactory.startDatabaseServer(DatabaseManagementServiceFactory.java:219) [neo4j-4.4.1.jar:4.4.1] at org.neo4j.graphdb.facade.DatabaseManagementServiceFactory.build(DatabaseManagementServiceFactory.java:181) [neo4j-4.4.1.jar:4.4.1] at org.neo4j.server.CommunityBootstrapper.createNeo(CommunityBootstrapper.java:36) [neo4j-4.4.1.jar:4.4.1] at org.neo4j.server.NeoBootstrapper.start(NeoBootstrapper.java:142) [neo4j-4.4.1.jar:4.4.1] at org.neo4j.server.NeoBootstrapper.start(NeoBootstrapper.java:95) [neo4j-4.4.1.jar:4.4.1] at org.neo4j.server.CommunityEntryPoint.main(CommunityEntryPoint.java:34) [neo4j-4.4.1.jar:4.4.1] Caused by: org.neo4j.kernel.internal.locker.FileLockException: Lock file has been locked by another process: /var/lib/neo4j/data/databases/store_lock. Please ensure no other process is using this database, and that the directory is writable (required even for read-only access) at org.neo4j.kernel.internal.locker.Locker.storeLockException(Locker.java:175) ~[neo4j-kernel-4.4.1.jar:4.4.1] at org.neo4j.kernel.internal.locker.Locker.checkLock(Locker.java:95) ~[neo4j-kernel-4.4.1.jar:4.4.1] at org.neo4j.kernel.internal.locker.GlobalFileLocker.checkLock(GlobalFileLocker.java:58) ~[neo4j-kernel-4.4.1.jar:4.4.1] at org.neo4j.kernel.internal.locker.GlobalLocker.checkLock(GlobalLocker.java:28) ~[neo4j-kernel-4.4.1.jar:4.4.1] at org.neo4j.kernel.internal.locker.LockerLifecycleAdapter.start(LockerLifecycleAdapter.java:36) ~[neo4j-kernel-4.4.1.jar:4.4.1] at org.neo4j.kernel.lifecycle.LifeSupport$LifecycleInstance.start(LifeSupport.java:442) ~[neo4j-common-4.4.1.jar:4.4.1] ... 7 more 2022-01-11 01:28:25.314+0000 INFO [o.n.g.f.DatabaseManagementServiceFactory] Shutdown started ``` It seems the apoc jar file is loaded, but call apoc still not working. There is an error of lock file, but not about apoc I guess. Thanks! ---
**Author:** ![joannelyu](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/joannelyu/32/21710_2.png) [@joannelyu](https://community.neo4j.com/u/joannelyu)\ **Post date:** [January 12, 2022, 9:49am UTC](https://community.neo4j.com/t/problem-with-installing-apoc-in-neo4j-server/50232/4 "2022-01-12T09:49:59Z")
> [@joannelyu](#): > > `call apoc.help("help");` Problem solved when I get ride of the lock file error.