Problem

when you start your application with skywalking agent,if you find this exception in your agent log which mean EnhanceRequireObjectCache can not be casted to EnhanceRequireObjectCache.eg:

ERROR 2018-05-07 21:31:24 InstMethodsInter :  class[class org.springframework.web.method.HandlerMethod] after method[getBean] intercept failure
java.lang.ClassCastException: org.apache.skywalking.apm.plugin.spring.mvc.commons.EnhanceRequireObjectCache cannot be cast to org.apache.skywalking.apm.plugin.spring.mvc.commons.EnhanceRequireObjectCache
	at org.apache.skywalking.apm.plugin.spring.mvc.commons.interceptor.GetBeanInterceptor.afterMethod(GetBeanInterceptor.java:45)
	at org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.InstMethodsInter.intercept(InstMethodsInter.java:105)
	at org.springframework.web.method.HandlerMethod.getBean(HandlerMethod.java)
	at org.springframework.web.servlet.handler.AbstractHandlerMethodExceptionResolver.shouldApplyTo(AbstractHandlerMethodExceptionResolver.java:47)
	at org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver.resolveException(AbstractHandlerExceptionResolver.java:131)
	at org.springframework.web.servlet.handler.HandlerExceptionResolverComposite.resolveException(HandlerExceptionResolverComposite.java:76)
	...

Reason

this exception may caused by some hot deployment tools(spring-boot-devtool) or some else which may change the classloader in runtime.

Resolve

1. Production environment does not appear this error because developer tools are automatically disabled,look spring-boot-devtools
2. If you want to debug in your development environment normally,you should remove such hot deployment package in your lib path temporarily.