Nullpointer Exception after upgrading to 4.4

I just upgraded to V 4.4 and Traccar does not start any more. Any idea?

pi@miniserver:/opt/traccar $ sudo java -jar tracker-server.jar conf/traccar.xml
[main] INFO com.zaxxer.hikari.HikariDataSource - HikariPool-1 - Starting...
[main] INFO com.zaxxer.hikari.HikariDataSource - HikariPool-1 - Start completed.
INFO 5/1/19 10:58 AM: liquibase: Clearing database change log checksums
INFO 5/1/19 10:58 AM: liquibase: Successfully acquired change log lock
INFO 5/1/19 10:58 AM: liquibase: Successfully released change log lock
INFO 5/1/19 10:58 AM: liquibase: Successfully acquired change log lock
INFO 5/1/19 10:58 AM: liquibase: Reading from PUBLIC.DATABASECHANGELOG
INFO 5/1/19 10:58 AM: liquibase: Reading from PUBLIC.DATABASECHANGELOG
INFO 5/1/19 10:58 AM: liquibase: Successfully released change log lock
[main] INFO org.eclipse.jetty.util.log - Logging initialized @26723ms
Exception in thread "main" java.lang.NullPointerException
        at org.traccar.database.BaseObjectManager.getAllItems(BaseObjectManager.java:121)
        at org.traccar.database.GroupsManager.getAllItems(GroupsManager.java:60)
        at org.traccar.database.PermissionsManager.refreshDeviceAndGroupPermissions(PermissionsManager.java:103)
        at org.traccar.database.PermissionsManager.<init>(PermissionsManager.java:55)
        at org.traccar.Context.init(Context.java:356)
        at org.traccar.Main.main(Main.java:35)

Looks like you are not using version 4.4.

ok - strange....
I just updated Java to Version 11 on my raspi, deleted the /opt/traccar directory (kept conf and data) and unpacked the 4.4 zip once more. Now it's working. Startup of the Service takes very long, but it's running. Thank you!

btw, in the Log there are the following entries, which are not clear for me. It's just to mention. On the next Traccar-update I'll do a complete fresh installation (incl. Raspi) anyway.

May 01 17:07:07 miniserver traccarserver[423]: WARNING: An illegal reflective access operation has occurred
May 01 17:07:07 miniserver traccarserver[423]: WARNING: Illegal reflective access by com.google.inject.internal.cglib.core.$ReflectUtils$1 (file:/opt/traccar/lib/guice-4.2.2.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
May 01 17:07:07 miniserver traccarserver[423]: WARNING: Please consider reporting this to the maintainers of com.google.inject.internal.cglib.core.$ReflectUtils$1
May 01 17:07:07 miniserver traccarserver[423]: WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
May 01 17:07:07 miniserver traccarserver[423]: WARNING: All illegal access operations will be denied in a future release