nested exception is java.lang.NoClassDefFoundError: org/springframework/boot/context/annotation/ImportCandidates

This exception occurs when the required class "org.springframework.boot.context.annotation.ImportCandidates" is not found during runtime. This class is typically used for importing candidate configuration classes in Spring Boot applications.

There are several reasons why this exception can occur:

1. Missing Dependency: The required dependency for the class might be missing in the classpath. In this case, you can add the required dependency to the build file (pom.xml for maven or build.gradle for Gradle).

2. Incorrect Version: It is possible that the required version of the dependency is not compatible with the application. In this case, you can try updating the version of the dependency.

3. Classpath Issue: The classpath might not be set up correctly, and the application is not able to find the class. Make sure that the classpath is set up correctly.

4. Corrupted Jar File: The jar file containing the class might be corrupted. In this case, try deleting the jar file and downloading it again.

To resolve this exception, check the dependencies and classpath setup for the application and ensure that the required class is available during runtime.