Upgrademanager fails at step "Membershiplink entries deletion for License Group" in Execute Server Migrators with "Error executing IncrementalUpdate Membershiplink entries deletion for License Group"

• Upgrademanager fails at step "Membershiplink entries deletion for License Group" in Execute Server Migrators
• Error From Upgrademanager.log: 

FATAL [main] com.ptc.windchill.upgrade.updates.UpdateRunner - com.ptc.windchill.upgrade.updates.UpdateExecutionException: Error executing IncrementalUpdate Membershiplink entries deletion for License Group (#394976282-1581670445244-2107577743-1-0-0-127)
Verschachtelte Ausnahme ist: (com.ptc.windchill.upgrade.updates.directives.directivesResource/39) com.ptc.windchill.upgrade.updates.DirectiveExecutionException: Method server code wt.org.UpdateMembershiplinkForLicenseGroups.deleteMemebershipLinkAndGroupForThingworx failed.  See nested exception for details
Verschachtelte Ausnahme ist: wt.util.WTException: java.lang.reflect.InvocationTargetException
Verschachtelte Ausnahme ist: java.lang.reflect.InvocationTargetException

• Error Message From Methodserver.log:

Verschachtelte Ausnahme ist: java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    .
	.
	.
Caused by: java.lang.NullPointerException
	at wt.org.StandardOrganizationServicesManager.members(StandardOrganizationServicesManager.java:5718)
	at wt.org.StandardOrganizationServicesManager._members(StandardOrganizationServicesManager.java:13494)
	at wt.org.StandardOrganizationServicesManager._members(StandardOrganizationServicesManager.java:13461)
	at wt.org.StandardOrganizationServicesManager.members(StandardOrganizationServicesManager.java:10876)
	at wt.org.StandardOrganizationServicesManager.members(StandardOrganizationServicesManager.java:5682)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at wt.services.ServiceFactory$ServerInvocationHandler.invoke(ServiceFactory.java:399)
	at com.sun.proxy.$Proxy65.members(Unknown Source)
	at wt.org.UpdateMembershiplinkForLicenseGroups.deleteMemebershipLinkAndGroupForThingworx(UpdateMembershiplinkForLicenseGroups.java:350)
	... 30 more