show aaa-users throws exception after ONU delete

karaf@root > aaa-users
09:44:22.461 ERROR [ShellUtil] Exception caught while executing command
java.lang.NullPointerException
        at org.opencord.aaa.cli.AaaShowUsersCommand.doExecute(AaaShowUsersCommand.java:68)
        at org.onosproject.cli.AbstractShellCommand.execute(AbstractShellCommand.java:159)
        at org.apache.karaf.shell.impl.action.command.ActionCommand.execute(ActionCommand.java:84)
        at org.apache.karaf.shell.impl.console.osgi.secured.SecuredCommand.execute(SecuredCommand.java:68)
        at org.apache.karaf.shell.impl.console.osgi.secured.SecuredCommand.execute(SecuredCommand.java:86)
        at org.apache.felix.gogo.runtime.Closure.executeCmd(Closure.java:599)
        at org.apache.felix.gogo.runtime.Closure.executeStatement(Closure.java:526)
        at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:415)
        at org.apache.felix.gogo.runtime.Pipe.doCall(Pipe.java:416)
        at org.apache.felix.gogo.runtime.Pipe.call(Pipe.java:229)
        at org.apache.felix.gogo.runtime.Pipe.call(Pipe.java:59)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at java.base/java.lang.Thread.run(Thread.java:834)
Error executing command: java.lang.NullPointerException
karaf@root >