springboot Application Run failed java.lang.NoClassDefFoundError

I am upgrading my spring boot app (fro 1.x to 2.x). I am getting below exception while deploying the App in WAS server.

(SpringApplication.java.821) ---- Application run failed java.lang.NoClasaDefFoundError: org.springframework.boot.env.PropertySourcesLoader at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:672)

I am upgrading to SpringBoot 2.1.6.RELEASE. Can anyone please help me on this.

Comment From: wilkinsona

Thanks for the report. It looks like you have some code that is not Spring Boot 2.0-compatible in your application or its dependencies. org.springframework.boot.env.PropertySourcesLoader doesn't exist in Spring Boot 2.0 yet something is try to load its class. This is resulting in a NoClassDefFoundError. If you need some help identify the code that is causing the problem, please ask on Stack Overflow or Gitter. As mentioned in the guidelines for contributing, we prefer to use GitHub issues only for bugs and enhancements.