1. Enable Debug Logging:

    • Open your application.properties or application.yml file.
    • Add or update the following line to enable debug logging:
  2. Check for Error Details:

    • Rerun your Spring Boot application with the 'debug' flag. You can do this by adding --debug as a command line argument when starting your application.
      ./mvnw spring-boot:run --debug
    • Look for more detailed error messages in the console logs. This should provide more information about the root cause of the problem.
  3. Check Dependencies:

    • Ensure that your project's dependencies and versions are compatible. You can check the Spring Boot compatibility matrix to make sure there are no conflicts.
  4. Check Application Context Configuration:

    • Verify that your @SpringBootApplication class is in the root package or a sub-package of the root package.
    • Make sure the main application class is annotated with @SpringBootApplication.
  5. Check Classpath:

    • Ensure that all the required dependencies are available in the classpath. Check your pom.xml (if using Maven) or build.gradle (if using Gradle) to make sure the dependencies are correctly specified.
  6. Check Component Scan:

    • If you are using component scanning, make sure that your components are in or under the package specified in @ComponentScan. By default, Spring Boot scans components in the same package or sub-packages as the main application class.

To enhance logging in your application, you can enable debugging by adding debug=true to the application.properties file or debug: true in the application.yml file for more detailed information.

If you wish to receive more specific log messages from a particular package, you can do so by adding a line like: logging.level.= For example: logging.level.org.springframework.context=DEBUG

These log messages can be instrumental in identifying the root cause of issues, such as why a specific exception occurred.

An error occurred while starting the AppContext. Multiple factors could be contributing to this issue. Could you please provide the full stacktrace?

It seems the demo controller is missing a slash '/' in its path declaration and lacks a controller implementation. Adding the missing slash might resolve the problem, but we need the complete stacktrace to confirm.