On downloading Drools Workbench from http://www.drools.org/download/download.html
It appears to be missing:
<groupId>org.uberfire</groupId>
<artifactId>uberfire-workbench</artifactId>

various imports complain as being missing, e.g.
import org.uberfire.client.mvp.AbstractWorkbenchPerspectiveActivity;
import org.uberfire.client.mvp.PlaceManager;

The service still starts but I get errors all the time:

SEVERE: Editor model couldn't be loaded from path: default://master@testRepo/TestProject/src/main/java/com/flybe/testproject/TestObj.java.
org.kie.workbench.common.screens.datamodeller.service.ServiceException: Data model couldn't be loaded, path: PathImpl{uri='default://master@testRepo/TestProject', fileName='TestProject', attrs={}}, projectPath: PathImpl{uri='default://master@testRepo/TestProject', fileName='TestProject', attrs={}}.
at org.kie.workbench.common.screens.datamodeller.backend.server.DataModelerServiceImpl.loadModel(DataModelerServiceImpl.java:342)
at org.kie.workbench.common.screens.datamodeller.backend.server.DataModelerServiceImpl.constructContent(DataModelerServiceImpl.java:251)
at org.kie.workbench.common.screens.datamodeller.backend.server.DataModelerServiceImpl.constructContent(DataModelerServiceImpl.java:121)
at org.kie.workbench.common.services.backend.service.KieService.loadContent(KieService.java:73)
at org.kie.workbench.common.screens.datamodeller.backend.server.DataModelerServiceImpl.loadContent(DataModelerServiceImpl.java:191)
at org.kie.workbench.common.screens.datamodeller.backend.server.DataModelerServiceImpl$Proxy$$$_WeldClientProxy.loadContent(DataModelerServiceImpl$Proxy$$$_WeldClientProxy.java)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.jboss.errai.bus.server.io.AbstractRPCMethodCallback.invokeMethodFromMessage(AbstractRPCMethodCallback.java:48)
at org.jboss.errai.bus.server.io.ValueReplyRPCEndpointCallback.callback(ValueReplyRPCEndpointCallback.java:22)
at org.jboss.errai.bus.server.io.RemoteServiceCallback.callback(RemoteServiceCallback.java:54)
at org.jboss.errai.cdi.server.CDIExtensionPoints$2.callback(CDIExtensionPoints.java:396)
at org.jboss.errai.bus.server.DeliveryPlan.deliver(DeliveryPlan.java:47)
at org.jboss.errai.bus.server.ServerMessageBusImpl.sendGlobal(ServerMessageBusImpl.java:293)
at org.jboss.errai.bus.server.SimpleDispatcher.dispatchGlobal(SimpleDispatcher.java:46)
at org.jboss.errai.bus.server.service.ErraiServiceImpl.store(ErraiServiceImpl.java:97)
at org.jboss.errai.bus.server.service.ErraiServiceImpl.store(ErraiServiceImpl.java:114)
at org.jboss.errai.bus.server.servlet.DefaultBlockingServlet.doPost(DefaultBlockingServlet.java:142)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.uberfire.ext.security.server.SecureHeadersFilter.doFilter(SecureHeadersFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.uberfire.ext.security.server.SecurityIntegrationFilter.doFilter(SecurityIntegrationFilter.java:64)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:614)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.kie.integration.tomcat.JACCValve.invoke(JACCValve.java:101)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.RuntimeException: com.google.inject.CreationException: Guice creation errors:

1) No implementation for org.kie.workbench.drools.client.perspectives.M2RepoPerspective annotated with interface org.eclipse.sisu.inject.TypeArguments$Implicit was bound.
at org.eclipse.sisu.wire.LocatorWiring

2) No implementation for org.kie.workbench.drools.client.perspectives.DroolsAuthoringNoContextNavigationPerspective annotated with interface org.eclipse.sisu.inject.TypeArguments$Implicit was bound.
at org.eclipse.sisu.wire.LocatorWiring

3) No implementation for org.kie.workbench.drools.client.perspectives.AdministrationPerspective annotated with interface org.eclipse.sisu.inject.TypeArguments$Implicit was bound.
at org.eclipse.sisu.wire.LocatorWiring

4) No implementation for org.kie.workbench.drools.client.perspectives.DroolsAuthoringPerspective annotated with interface org.eclipse.sisu.inject.TypeArguments$Implicit was bound.
at org.eclipse.sisu.wire.LocatorWiring

4 errors
at org.kie.scanner.embedder.MavenProjectLoader.parseMavenPom(MavenProjectLoader.java:44)
at org.kie.scanner.embedder.MavenProjectLoader.parseMavenPom(MavenProjectLoader.java:35)
at org.kie.scanner.ArtifactResolver.getResolverFor(ArtifactResolver.java:100)
at org.kie.scanner.KieModuleMetaDataImpl.<init>(KieModuleMetaDataImpl.java:68)
at org.kie.scanner.KieModuleMetaData$Factory.newKieModuleMetaData(KieModuleMetaData.java:30)
at org.kie.workbench.common.screens.datamodeller.backend.server.DataModelerServiceImpl.getProjectClassLoader(DataModelerServiceImpl.java:1214)
at org.kie.workbench.common.screens.datamodeller.backend.server.DataModelerServiceImpl.loadModel(DataModelerServiceImpl.java:315)
... 48 more
Caused by: com.google.inject.CreationException: Guice creation errors: