Hibernate Tools - Unhandled event loop exception - eclipse - eclipse

Question

I have configured hibernate tools and after few hours of normal usage something got corrupted and every time I type a HQL query the error below appears
Unhandled event loop exception
Java version installed is java 8 but the project on which I run my queries uses java 1.7
I think it is not a memory related problem. I have 32 GB installed on my machine of which only 2GB are dedicated to eclipse env. I run the garbage collector and despite I have more than 1.8 GB of memory available I still get the error.
I have also uninstalled and reinstalled the hibernate tools plugin with no good result
Any help highly appreciated
Exception Stack Trace:
java.lang.NullPointerException
at org.eclipse.ui.internal.WorkbenchPage.busyShowView(WorkbenchPage.java:1270)
at org.eclipse.ui.internal.WorkbenchPage$12.run(WorkbenchPage.java:4211)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.showView(WorkbenchPage.java:4207)
at org.eclipse.ui.internal.WorkbenchPage.showView(WorkbenchPage.java:4187)
at org.hibernate.eclipse.hqleditor.HQLEditor.executeQuery(HQLEditor.java:442)
at org.hibernate.eclipse.console.actions.ExecuteQueryAction.execute(ExecuteQueryAction.java:82)
at org.hibernate.eclipse.console.actions.ExecuteQueryAction.run(ExecuteQueryAction.java:55)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:473)
at org.hibernate.eclipse.console.actions.ExecuteQueryAction.runWithEvent(ExecuteQueryAction.java:59)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:595)
at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:511)
at org.eclipse.jface.action.ActionContributionItem$6.handleEvent(ActionContributionItem.java:462)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4481)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1329)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3819)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3430)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$4.run(PartRenderingEngine.java:1127)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:337)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1018)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:156)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:654)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:337)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:598)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:139)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:380)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:235)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:669)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:608)
at org.eclipse.equinox.launcher.Main.run(Main.java:1515)
at org.eclipse.equinox.launcher.Main.main(Main.java:1488)
Session Data
eclipse.buildId=4.5.1.M20150904-0015
java.version=1.8.0_66
java.vendor=Oracle Corporation
BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_GB
Framework arguments: -product org.eclipse.epp.package.jee.product
Command-line arguments: -os linux -ws gtk -arch x86_64 -product org.eclipse.epp.package.jee.product
Thanks