Sonatype Nexus upgraded to 3.19.1 from 3.17.1 and wont start

Question

I upgraded Sonatype Nexus to 3.19.1 from 3.17.1.
Now it wont start and I checked the logs.

Log says " Missing recipe: helm-proxy"
I did setup helm proxy plugin as per link Nexus Helm recipe
Complete log is below.

 2019-11-01 15:29:45,358+1100 ERROR [FelixStartLevel]  *SYSTEM org.sonatype.nexus.repository.manager.internal.RepositoryManagerImpl - Failed transition: NEW -> STARTED
java.lang.IllegalStateException: Missing recipe: helm-proxy
        at com.google.common.base.Preconditions.checkState(Preconditions.java:585)
        at org.sonatype.nexus.repository.manager.internal.RepositoryManagerImpl.recipe(RepositoryManagerImpl.java:161)
        at org.sonatype.nexus.repository.manager.internal.RepositoryManagerImpl.newRepository(RepositoryManagerImpl.java:179)
        at org.sonatype.nexus.repository.manager.internal.RepositoryManagerImpl.restoreRepositories(RepositoryManagerImpl.java:271)
        at org.sonatype.nexus.repository.manager.internal.RepositoryManagerImpl.doStart(RepositoryManagerImpl.java:253)
        at org.sonatype.nexus.common.stateguard.StateGuardLifecycleSupport.start(StateGuardLifecycleSupport.java:67)
        at org.sonatype.nexus.common.stateguard.MethodInvocationAction.run(MethodInvocationAction.java:39)
        at org.sonatype.nexus.common.stateguard.StateGuard$TransitionImpl.run(StateGuard.java:193)
        at org.sonatype.nexus.common.stateguard.TransitionsInterceptor.invoke(TransitionsInterceptor.java:56)
        at org.sonatype.nexus.extender.NexusLifecycleManager.startComponent(NexusLifecycleManager.java:199)
        at org.sonatype.nexus.extender.NexusLifecycleManager.to(NexusLifecycleManager.java:111)
        at org.sonatype.nexus.extender.NexusContextListener.moveToPhase(NexusContextListener.java:311)
        at org.sonatype.nexus.extender.NexusContextListener.frameworkEvent(NexusContextListener.java:208)
        at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1431)
        at org.apache.felix.framework.FrameworkStartLevelImpl.run(FrameworkStartLevelImpl.java:308)
        at java.lang.Thread.run(Thread.java:748)
2019-11-01 15:29:45,379+1100 ERROR [FelixStartLevel]  *SYSTEM org.sonatype.nexus.extender.NexusContextListener - Failed to start nexus
java.lang.IllegalStateException: Missing recipe: helm-proxy
        at com.google.common.base.Preconditions.checkState(Preconditions.java:585)
        at org.sonatype.nexus.repository.manager.internal.RepositoryManagerImpl.recipe(RepositoryManagerImpl.java:161)
        at org.sonatype.nexus.repository.manager.internal.RepositoryManagerImpl.newRepository(RepositoryManagerImpl.java:179)
        at org.sonatype.nexus.repository.manager.internal.RepositoryManagerImpl.restoreRepositories(RepositoryManagerImpl.java:271)
        at org.sonatype.nexus.repository.manager.internal.RepositoryManagerImpl.doStart(RepositoryManagerImpl.java:253)
        at org.sonatype.nexus.common.stateguard.StateGuardLifecycleSupport.start(StateGuardLifecycleSupport.java:67)
        at org.sonatype.nexus.common.stateguard.MethodInvocationAction.run(MethodInvocationAction.java:39)
        at org.sonatype.nexus.common.stateguard.StateGuard$TransitionImpl.run(StateGuard.java:193)
        at org.sonatype.nexus.common.stateguard.TransitionsInterceptor.invoke(TransitionsInterceptor.java:56)
        at org.sonatype.nexus.extender.NexusLifecycleManager.startComponent(NexusLifecycleManager.java:199)
        at org.sonatype.nexus.extender.NexusLifecycleManager.to(NexusLifecycleManager.java:111)
        at org.sonatype.nexus.extender.NexusContextListener.moveToPhase(NexusContextListener.java:311)
        at org.sonatype.nexus.extender.NexusContextListener.frameworkEvent(NexusContextListener.java:208)
        at org.apache.felix.framework.Felix.setActiveStartLevel(Felix.java:1431)
        at org.apache.felix.framework.FrameworkStartLevelImpl.run(FrameworkStartLevelImpl.java:308)
        at java.lang.Thread.run(Thread.java:748)

Any idea whats going wrong. If I choose a new empty data directory, Nexus starts. But I will lose my existing data.

Update
I was able to bring it up. Downloaded a fresh copy of nexus-repository-helm-0.0.12.jar file and nexus is back online. However I still can't bring it up as a service. I have to execute nexus/bin/nexus start to get it up. No logs in nexus.log as well.

Log from journal -xe

Nov 01 16:54:29 lndevopsnx  polkitd[867]: Unregistered Authentication Agent for unix-process:6536:123145 (system bus name :1.60, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8) (disconnected from bus)
Nov 01 16:54:29 lndevopsnx systemd[1]: Started nexus service.
-- Subject: Unit nexus.service has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit nexus.service has finished starting up.
--
-- The start-up result is done.
Nov 01 16:54:29 lndevopsnx systemd[1]: nexus.service: main process exited, code=exited, status=255/n/a
Nov 01 16:54:30 lnpdevopsnx nexus[6732]: Shutting down nexus
Nov 01 16:54:30 lndevopsnx nexus[6732]: nexus is not running.
Nov 01 16:54:30 lndevopsnx systemd[1]: Unit nexus.service entered failed state.

Answer 1

I was able to bring it up. Downloaded a fresh copy of nexus-repository-helm-0.0.12.jar file and nexus is back online. However I still can't bring it up as a service. I have to execute nexus/bin/nexus start to get it up.