org.springframework.context.ApplicationContextException: Unable to start web server; nested excepti

on is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat server

This exception typically occurs when the Spring Boot application fails to start the embedded web server, in this case, the Tomcat server. It can be caused by various reasons such as port conflicts, misconfiguration, or missing dependencies.

To troubleshoot this issue, you can follow these steps:

1. Check for port conflicts: Make sure the port specified for the embedded web server (usually port 8080 by default) is not being used by any other process. You can change the server port in the application.properties or application.yml file.

2. Review your configuration: Double-check your application's configuration files to ensure that all required properties and dependencies are correctly set up. Pay attention to properties related to the web server, such as server.port, server.servlet.context-path, etc.

3. Verify dependencies: Ensure that you have all the necessary dependencies for the embedded web server, such as Tomcat, added to your project's build file (e.g., pom.xml for Maven).

4. Check log files: Look for any additional error messages or stack traces in the application log files (e.g., console output, log files in the logs directory). They might provide more specific details about the cause of the issue.

If none of the above steps resolve the issue, please provide more details about your application setup and any relevant error messages from the logs, so I can assist you further.