Caused by: java.lang.IllegalStateException: Tomcat connector in failed state

I am using embedded tomcat using spring boot. While running the application I getting following error. What could be wrong?

org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat servlet container
    at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.start(TomcatEmbeddedServletContainer.java:165) ~[spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.startEmbeddedServletContainer(EmbeddedWebApplicationContext.java:293) ~[spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.finishRefresh(EmbeddedWebApplicationContext.java:141) ~[spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541) ~[spring-context-4.2.4.RELEASE.jar:4.2.4.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) [spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) [spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1191) [spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1180) [spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    at com.concretepage.SocialApplication.main(SocialApplication.java:11) [classes/:na]
Caused by: java.lang.IllegalStateException: Tomcat connector in failed state
    at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.start(TomcatEmbeddedServletContainer.java:159) ~[spring-boot-1.3.2.RELEASE.jar:1.3.2.RELEASE]
    ... 10 common frames omitted

It is possible that tomcat is already running with same port. You kill the java process and start the application again. It may fix your problem.