expression parameters.parseContent is undefined

我导入了struts2-dojo-plugin.jar ，页面也该成了<sx:head/>,为什么还是报
Expression parameters.parseContent is undefined on line 45, column 28 in template/ajax/head.ftl. - Class: freeer.core.TemplateObject
File: TemplateObject.java
Method: assertNonNull
Line: 124 - freeer/core/TemplateObject.java:124:-1
at org.apache.struts2.components.UIBean.end(UIBean.java:515)
at org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:42)
at org.apache.jsp.LeftTree_jsp._jspx_meth_s_005fhead_005f0(LeftTree_jsp.java:173)
at org.apache.jsp.LeftTree_jsp._jspService(LeftTree_jsp.java:85)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:389)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:319)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:270)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:191)
at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:389)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:220)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:191)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:227)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:211)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:817)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:623)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:444)
at java.lang.Thread.run(Thread.java:619)
Caused by: freeer.core.InvalidReferenceException: Expression parameters.parseContent is undefined on line 45, column 28 in template/ajax/head.ftl.
at freeer.core.TemplateObject.assertNonNull(TemplateObject.java:124)
at freeer.core.TemplateObject.invalidTypeException(TemplateObject.java:134)
at freeer.core.BuiltIn$stringBI._getAsTemplateModel(BuiltIn.java:361)
at freeer.core.Expression.getAsTemplateModel(Expression.java:89)
at freeer.core.Expression.getStringValue(Expression.java:93)
at freeer.core.DollarVariable.accept(DollarVariable.java:76)
at freeer.core.Environment.visit(Environment.java:208)
at freeer.core.MixedContent.accept(MixedContent.java:92)
at freeer.core.Environment.visit(Environment.java:208)
at freeer.core.Environment.process(Environment.java:188)
at freeer.template.Template.process(Template.java:237)
at org.apache.struts2.components.template.FreeerTemplateEngine.renderTemplate(FreeerTemplateEngine.java:182)
at org.apache.struts2.components.UIBean.mergeTemplate(UIBean.java:559)
at org.apache.struts2.components.UIBean.end(UIBean.java:513)
... 24 more