环境：Tomcat6.0 Eclipse3.4 jdk1.5
一周前我用的时候还可以运行，期间我在机器上装了一个MyEclipse6.0在MyEclipse中运行struts2的application就出现此错误，之后我把MyEclipse卸载，又重装了Tomcat，启动Eclipse运行软件还是有这个错误
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: javax.servlet.ServletException: java.lang.NoClassDefFoundError: javax/el/ELResolver
com.neusoft.unieap.service.security.ui.webapp.UniEAPSecurityEnforcementFilter.doFilter(UniEAPSecurityEnforcementFilter.java:174)
……
org.ecside.filter.ECSideFilter.doFilter(ECSideFilter.java:161)
com.neusoft.unieap.comp.transcoding.TranscodingFilter.doFilter(TranscodingFilter.java:35)
root cause
javax.servlet.ServletException: java.lang.NoClassDefFoundError: javax/el/ELResolver
org.apache