Redundant remove call

[kazuyoshi]

When I call goTo method of PlaceController, I get redundant remove
call assertion error.
Can anyone help me?
What would be the problem?

My Place class is:

import com.google.gwt.place.shared.Place;
import com.google.gwt.place.shared.PlaceTokenizer;

public class WorkbenchPlace extends Place {
private String trasetUni;
private String traKey;

public WorkbenchPlace(String trasetUni) {
this.trasetUni = trasetUni;
this.traKey = null;
}

public WorkbenchPlace(String trasetUni, String traKey) {
this.trasetUni = trasetUni;
this.traKey = traKey;
}

public String getTrasetUni() {
return trasetUni;
}

public String getTraKey() {
return traKey;
}

public static class Tokenizer implements
PlaceTokenizer<WorkbenchPlace> {
@Override
public String getToken(WorkbenchPlace place) {
return place.getTrasetUni() + ";"
+ (place.getTraKey() == null ? "" : place.getTraKey());
}

@Override
public WorkbenchPlace getPlace(String token) {
String[] t = token.split(";");
String trakey = null;
if (t.length >= 2 && !t[1].isEmpty()) {
trakey = t[1];
}
return new WorkbenchPlace(t[0], trakey);
}
}
}

And the error message is:

15:21:09.270 [ERROR] Uncaught exception escaped
com.google.gwt.event.shared.UmbrellaException: One or more exceptions
caught, see full set in UmbrellaException#getCauses
at
com.google.gwt.event.shared.SimpleEventBus.doFire(SimpleEventBus.java:
214)
at
com.google.gwt.event.shared.SimpleEventBus.fireEvent(SimpleEventBus.java:
103)
at
com.google.gwt.event.shared.HandlerManager.fireEvent(HandlerManager.java:
96)
at
com.google.gwt.user.client.impl.HistoryImpl.fireEvent(HistoryImpl.java:
74)
at
com.google.gwt.event.logical.shared.ValueChangeEvent.fire(ValueChangeEvent.java:
43)
at
com.google.gwt.user.client.impl.HistoryImpl.fireHistoryChangedImpl(HistoryImpl.java:
81)
at
com.google.gwt.user.client.impl.HistoryImpl.newItemOnEvent(HistoryImpl.java:
128)
at sun.reflect.GeneratedMethodAccessor52.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at
com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at
com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
157)
at
com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:
326)
at
com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:
207)
at
com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:
126)
at
com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:
561)
at
com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:
269)
at
com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:
91)
at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:214)
at sun.reflect.GeneratedMethodAccessor20.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at
com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at
com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
157)
at
com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:
281)
at
com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:
531)
at
com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:
352)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.AssertionError: redundant remove call
at
com.google.gwt.event.shared.SimpleEventBus.doRemoveNow(SimpleEventBus.java:
228)
at com.google.gwt.event.shared.SimpleEventBus.access
$1(SimpleEventBus.java:224)
at com.google.gwt.event.shared.SimpleEventBus
$3.execute(SimpleEventBus.java:247)
at
com.google.gwt.event.shared.SimpleEventBus.handleQueuedAddsAndRemoves(SimpleEventBus.java:
303)
at
com.google.gwt.event.shared.SimpleEventBus.doFire(SimpleEventBus.java:
219)
at
com.google.gwt.event.shared.SimpleEventBus.fireEvent(SimpleEventBus.java:
103)
at
com.google.gwt.place.shared.PlaceController.goTo(PlaceController.java:
115)
at
com.google.gwt.place.shared.PlaceHistoryHandler.handleHistoryToken(PlaceHistoryHandler.java:
179)
at com.google.gwt.place.shared.PlaceHistoryHandler.access
$2(PlaceHistoryHandler.java:162)
at com.google.gwt.place.shared.PlaceHistoryHandler
$2.onValueChange(PlaceHistoryHandler.java:141)
at
com.google.gwt.event.logical.shared.ValueChangeEvent.dispatch(ValueChangeEvent.java:
128)
at
com.google.gwt.event.logical.shared.ValueChangeEvent.dispatch(ValueChangeEvent.java:
1)
at
com.google.gwt.event.shared.SimpleEventBus.doFire(SimpleEventBus.java:
204)
at
com.google.gwt.event.shared.SimpleEventBus.fireEvent(SimpleEventBus.java:
103)
at
com.google.gwt.event.shared.HandlerManager.fireEvent(HandlerManager.java:
96)
at
com.google.gwt.user.client.impl.HistoryImpl.fireEvent(HistoryImpl.java:
74)
at
com.google.gwt.event.logical.shared.ValueChangeEvent.fire(ValueChangeEvent.java:
43)
at
com.google.gwt.user.client.impl.HistoryImpl.fireHistoryChangedImpl(HistoryImpl.java:
81)
at
com.google.gwt.user.client.impl.HistoryImpl.newItemOnEvent(HistoryImpl.java:
128)
at sun.reflect.GeneratedMethodAccessor52.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at
com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at
com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
157)
at
com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:
326)
at
com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:
207)
at
com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:
126)
at
com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:
561)
at
com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:
269)
at
com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:
91)
at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:214)
at sun.reflect.GeneratedMethodAccessor20.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at
com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at
com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
157)
at
com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:
281)
at
com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:
531)
at
com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:
352)
at java.lang.Thread.run(Unknown Source)