Unable to install Google Web Toolkit Designer from Central

org.eclipse.core.runtime.CoreException: Operation details
	at org.eclipse.mylyn.internal.discovery.ui.PrepareInstallProfileJob_e_3_6.resolveInstall(PrepareInstallProfileJob_e_3_6.java:198)
	at org.eclipse.mylyn.internal.discovery.ui.PrepareInstallProfileJob_e_3_6.run(PrepareInstallProfileJob_e_3_6.java:99)
	at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)
Contains: Cannot complete the install because one or more required items could not be found.
Contains: Software being installed: GWT Designer GPE 3.1.2.r42x201303061641 (com.google.gdt.eclipse.designer.gpe.feature.feature.group 3.1.2.r42x201303061641)
Contains: Missing requirement: GWT Designer GPE 3.1.2.r42x201303061641 (com.google.gdt.eclipse.designer.gpe.feature.feature.group 3.1.2.r42x201303061641) requires 'org.eclipse.wb.core.ui 0.0.0' but it could not be found