Spring boot (2.0.0 to 2.1.8) & Neo4j-OGM (3.0.1 to 3.1.1) upgrade sessionFactory issue - spring-boot

Question

I'm trying to upgrade spring boot 2.0.0 to 2.1.8 and updated Neo4j OGM to the appropriate version mentioned in the neo4j documentation here
I also referred to the migration documentation here. which explains for 2.0 to 3.0 and it looks like the configuration is similar between 3.0 and 3.1. I may be wrong here
here is my code https://github.com/nkumarclm/sprintboot2.1_neo4jogm3.1 and getting an exception while wiring the sessionFactory to the Spring boot data neo4j.
Note: I was originally migrating my application from Spring boot 1.5 to 2.0 as a first step before jumping to 2.1 as recommended here https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.0-Migration-Guide#upgrade-to-spring-boot-2
so the provided code https://github.com/nkumarclm/sprintboot2.1_neo4jogm3.1 works fine with the spring boot version 2.0.0 and Neo4j OGM 3.0.1 but not with Spring boot 2.1.8 & Neo4j OGM 3.1.1
Error:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in class path resource [org/springframework/boot/autoconfigure/data/neo4j/Neo4jDataAutoConfiguration$Neo4jOgmSessionFactoryConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.neo4j.ogm.session.SessionFactory]: Factory method 'sessionFactory' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:627) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:607) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:845) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
I think I'm definitely missing something here and any suggestion related to this would be of great help.
Thanks very much in advance for your time and effort on this problem.

Answer 1

I came a cross a similar error when I tried to upgrade from 2.1.7 to 2.1.8 so you might want to try 2.1.7 and see if that works.
Further I found out the inflicting class had a java.nio.file.Path property which was the cause for my problem.
My gradle:
id 'org.springframework.boot' version '2.1.9.RELEASE'
implementation 'org.springframework.boot:spring-boot-starter-data-neo4j'
implementation 'org.springframework.boot:spring-boot-starter-web'
implementation group: 'org.modelmapper', name: 'modelmapper', version: '2.3.5'
Maybe it helps.