我正在尝试使用Guvnor UI创建drools规则，但获得以下异常。使用Java 7.在创建测试场景和验证规则时出错。
使用JBoss 7.1.1-Final
Drools libraries 6.4.0.Final
14:20:20,878 ERROR [org.drools.guvnor.server.ServiceImplementation] (http--0.0.0.0-8080-3) Unable to build asset.: org.drools.RuntimeDroolsException: Unable to load dialect 'org.drools.rule.builder.dialect.java.JavaDialectConfiguration:java:org.drools.rule.builder.dialect.java.JavaDialectConfiguration'
at org.drools.compiler.PackageBuilderConfiguration.addDialect(PackageBuilderConfiguration.java:283) [drools-compiler-5.1.1.jar:5.1.1]
at org.drools.compiler.PackageBuilderConfiguration.buildDialectConfigurationMap(PackageBuilderConfiguration.java:268) [drools-compiler-5.1.1.jar:5.1.1]
at org.drools.compiler.PackageBuilderConfiguration.init(PackageBuilderConfiguration.java:181) [drools-compiler-5.1.1.jar:5.1.1]
at org.drools.compiler.PackageBuilderConfiguration.<init>(PackageBuilderConfiguration.java:143) [drools-compiler-5.1.1.jar:5.1.1]
at org.drools.guvnor.server.builder.BRMSPackageBuilder.getInstance(BRMSPackageBuilder.java:98) [classes:]
at org.drools.guvnor.server.builder.ContentPackageAssembler.createBuilder(ContentPackageAssembler.java:160) [classes:]
at org.drools.guvnor.server.builder.ContentPackageAssembler.<init>(ContentPackageAssembler.java:149) [classes:]
at org.drools.guvnor.server.ServiceImplementation.buildAsset(ServiceImplementation.java:1813) [classes:]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_80]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_80]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_80]
at java.lang.reflect.Method.invoke(Method.java:606) [rt.jar:1.7.0_80]
at org.jboss.seam.util.Reflections.invoke(Reflections.java:22) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:31) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.transaction.RollbackInterceptor.aroundInvoke(RollbackInterceptor.java:28) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.core.BijectionInterceptor.aroundInvoke(BijectionInterceptor.java:77) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:44) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.security.SecurityInterceptor.aroundInvoke(SecurityInterceptor.java:157) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:166) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.intercept.JavaBeanInterceptor.invoke(JavaBeanInterceptor.java:102) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.drools.guvnor.server.ServiceImplementation_$$_javassist_4.buildAsset(ServiceImplementation_$$_javassist_4.java) [classes:]
at org.drools.guvnor.server.RepositoryServiceServlet.buildAsset(RepositoryServiceServlet.java:251) [classes:]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_80]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_80]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_80]
at java.lang.reflect.Method.invoke(Method.java:606) [rt.jar:1.7.0_80]
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:562) [gwt-servlet-2.0.4.jar:]
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:188) [gwt-servlet-2.0.4.jar:]
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:224) [gwt-servlet-2.0.4.jar:]
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62) [gwt-servlet-2.0.4.jar:]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:754) [jboss-servlet-api_3.0_spec-1.0.0.Final.jar:1.0.0.Final]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847) [jboss-servlet-api_3.0_spec-1.0.0.Final.jar:1.0.0.Final]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
at org.jboss.seam.web.ContextFilter$1.process(ContextFilter.java:42) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.servlet.ContextualHttpServletRequest.run(ContextualHttpServletRequest.java:53) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.jboss.seam.web.ContextFilter.doFilter(ContextFilter.java:37) [org.jboss.seam-jboss-seam-2.1.0.GA.jar:2.1.0.GA]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161) [jbossweb-7.0.13.Final.jar:]
at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:153) [jboss-as-web-7.1.1.Final.jar:7.1.1.Final]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:368) [jbossweb-7.0.13.Final.jar:]
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) [jbossweb-7.0.13.Final.jar:]
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:671) [jbossweb-7.0.13.Final.jar:]
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930) [jbossweb-7.0.13.Final.jar:]
at java.lang.Thread.run(Thread.java:745) [rt.jar:1.7.0_80]
Caused by: org.drools.RuntimeDroolsException: value '1.7' is not a valid language level
at org.drools.rule.builder.dialect.java.JavaDialectConfiguration.getDefaultLanguageLevel(JavaDialectConfiguration.java:162) [drools-compiler-5.1.1.jar:5.1.1]
at org.drools.rule.builder.dialect.java.JavaDialectConfiguration.init(JavaDialectConfiguration.java:57) [drools-compiler-5.1.1.jar:5.1.1]
at org.drools.compiler.PackageBuilderConfiguration.addDialect(PackageBuilderConfiguration.java:279) [drools-compiler-5.1.1.jar:5.1.1]
... 55 more