Stack trace editing issue

I think it's something to do with your field validator? Occurs when editing a page every time for me.

2004-02-05 21:45:49,533 WARN [opensymphony.xwork.util.OgnlUtil] Caught OgnlException while setting property 'fieldName' on type 'com.opensymphony.xwork.validator.validators.ExpressionValidator'.
ognl.NoSuchPropertyException: fieldName
at ognl.ObjectPropertyAccessor.setProperty(ObjectPropertyAccessor.java:133)
at ognl.OgnlRuntime.setProperty(OgnlRuntime.java:1460)
at ognl.ASTProperty.setValueBody(ASTProperty.java:105)
at ognl.SimpleNode.setValue(SimpleNode.java:239)
at ognl.Ognl.setValue(Ognl.java:478)
at com.opensymphony.xwork.util.OgnlUtil.internalSetProperty(OgnlUtil.java:183)
at com.opensymphony.xwork.util.OgnlUtil.setProperties(OgnlUtil.java:72)
at com.opensymphony.xwork.util.OgnlUtil.setProperties(OgnlUtil.java:95)
at com.opensymphony.xwork.util.OgnlUtil.setProperties(OgnlUtil.java:84)
at com.opensymphony.xwork.validator.ValidatorFactory.getValidator(ValidatorFactory.java:55)
at com.opensymphony.xwork.validator.ValidatorFileParser.addValidators(ValidatorFileParser.java:150)
at com.opensymphony.xwork.validator.ValidatorFileParser.parseActionValidators(ValidatorFileParser.java:98)
at com.opensymphony.xwork.validator.ActionValidatorManager.loadFile(ActionValidatorManager.java:142)
at com.opensymphony.xwork.validator.ActionValidatorManager.buildClassValidators(ActionValidatorManager.java:97)
at com.opensymphony.xwork.validator.ActionValidatorManager.buildValidators(ActionValidatorManager.java:115)
at com.opensymphony.xwork.validator.ActionValidatorManager.getValidators(ActionValidatorManager.java:46)
at com.opensymphony.xwork.validator.ActionValidatorManager.validate(ActionValidatorManager.java:59)
at com.opensymphony.xwork.validator.ActionValidatorManager.validate(ActionValidatorManager.java:55)
at com.opensymphony.xwork.validator.ValidationInterceptor.before(ValidationInterceptor.java:36)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:36)
at com.atlassian.confluence.core.ConfluenceValidationInterceptor.intercept(ConfluenceValidationInterceptor.java:18)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:170)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:37)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:170)
at com.atlassian.confluence.security.actions.PermissionCheckInterceptor.intercept(PermissionCheckInterceptor.java:40)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:170)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:37)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:170)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:37)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:170)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:37)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:170)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:37)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:170)
at com.opensymphony.xwork.DefaultActionProxy.execute(DefaultActionProxy.java:116)
at com.opensymphony.webwork.dispatcher.ServletDispatcher.serviceAction(ServletDispatcher.java:182)
at com.opensymphony.webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:162)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:103)
at com.caucho.server.http.FilterChainServlet.doFilter(FilterChainServlet.java:96)
at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:129)
at com.atlassian.confluence.util.profiling.ProfilingPageFilter.parsePage(ProfilingPageFilter.java:36)
at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:61)
at com.caucho.server.http.FilterChainFilter.doFilter(FilterChainFilter.java:88)
at com.atlassian.seraph.filter.SecurityFilter.doFilter(SecurityFilter.java:161)
at com.caucho.server.http.FilterChainFilter.doFilter(FilterChainFilter.java:88)
at com.atlassian.seraph.filter.LoginFilter.doFilter(LoginFilter.java:181)
at com.caucho.server.http.FilterChainFilter.doFilter(FilterChainFilter.java:88)
at com.atlassian.johnson.filters.JohnsonFilter.doFilter(JohnsonFilter.java:96)
at com.caucho.server.http.FilterChainFilter.doFilter(FilterChainFilter.java:88)
at org.springframework.orm.hibernate.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:83)
at com.atlassian.confluence.setup.SpringSessionInViewFilter.doFilterInternal(SpringSessionInViewFilter.java:32)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:39)
at com.caucho.server.http.FilterChainFilter.doFilter(FilterChainFilter.java:88)
at com.atlassian.util.profiling.filters.ProfilingFilter.doFilter(ProfilingFilter.java:132)
at com.caucho.server.http.FilterChainFilter.doFilter(FilterChainFilter.java:88)
at com.atlassian.core.filters.AbstractEncodingFilter.doFilter(AbstractEncodingFilter.java:38)
at com.caucho.server.http.FilterChainFilter.doFilter(FilterChainFilter.java:88)
at com.caucho.server.http.Invocation.service(Invocation.java:315)
at com.caucho.server.http.CacheInvocation.service(CacheInvocation.java:135)
at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:246)
at com.caucho.server.http.HttpRequest.handleConnection(HttpRequest.java:164)
at com.caucho.server.TcpConnection.run(TcpConnection.java:139)
at java.lang.Thread.run(Thread.java:534)