In the System Perspective when click to the Properties and then to the System Manager an Exception will throw:
!ENTRY org.eclipse.ui.workbench 4 0 2013-08-19 14:46:56.431
!MESSAGE WARNING: Prevented recursive attempt to activate part org.eclipse.ui.views.PropertySheet while still in the middle of activating part org.fordiac.systemmanagement.ui.views.SystemTreeView
!STACK 0
java.lang.RuntimeException: WARNING: Prevented recursive attempt to activate part org.eclipse.ui.views.PropertySheet while still in the middle of activating part org.fordiac.systemmanagement.ui.views.SystemTreeView
at org.eclipse.ui.internal.WorkbenchPage.setActivePart(WorkbenchPage.java:3586)
at org.eclipse.ui.internal.WorkbenchPage.requestActivation(WorkbenchPage.java:3159)
at org.eclipse.ui.internal.PartPane.requestActivation(PartPane.java:279)
at org.eclipse.ui.internal.PartPane.handleEvent(PartPane.java:237)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1077)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1058)
at org.eclipse.swt.widgets.Shell.setActiveControl(Shell.java:1447)
at org.eclipse.swt.widgets.Control.sendFocusEvent(Control.java:2836)
at org.eclipse.swt.widgets.Widget.wmSetFocus(Widget.java:2403)
at org.eclipse.swt.widgets.Control.WM_SETFOCUS(Control.java:5152)
at org.eclipse.swt.widgets.Tree.WM_SETFOCUS(Tree.java:7037)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:4598)
at org.eclipse.swt.widgets.Tree.windowProc(Tree.java:5937)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4972)
at org.eclipse.swt.internal.win32.OS.SetFocus(Native Method)
at org.eclipse.swt.widgets.Control.forceFocus(Control.java:1098)
at org.eclipse.swt.widgets.Control.setFocus(Control.java:3303)
at org.eclipse.swt.widgets.Composite.setFocus(Composite.java:1040)
at org.eclipse.swt.widgets.Composite.setFocus(Composite.java:1038)
at org.eclipse.swt.widgets.Control.fixFocus(Control.java:1053)
at org.eclipse.swt.widgets.Control.setVisible(Control.java:3762)
at org.eclipse.ui.part.PageBook.showPage(PageBook.java:111)
at org.eclipse.ui.part.PageBookView.showPageRec(PageBookView.java:979)
at org.eclipse.ui.part.PageBookView.partActivated(PageBookView.java:758)
at org.eclipse.ui.views.properties.PropertySheet.partActivated(PropertySheet.java:323)
at org.eclipse.ui.part.PageBookView$4.partActivated(PageBookView.java:1014)
at org.eclipse.ui.internal.PartListenerList2$1.run(PartListenerList2.java:70)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.runtime.Platform.run(Platform.java:888)
at org.eclipse.ui.internal.PartListenerList2.fireEvent(PartListenerList2.java:55)
at org.eclipse.ui.internal.PartListenerList2.firePartActivated(PartListenerList2.java:68)
at org.eclipse.ui.internal.PartService.firePartActivated(PartService.java:192)
at org.eclipse.ui.internal.PartService.setActivePart(PartService.java:306)
at org.eclipse.ui.internal.WorkbenchPagePartList.fireActivePartChanged(WorkbenchPagePartList.java:57)
at org.eclipse.ui.internal.PartList.setActivePart(PartList.java:136)
at org.eclipse.ui.internal.WorkbenchPage.setActivePart(WorkbenchPage.java:3636)
at org.eclipse.ui.internal.WorkbenchPage.requestActivation(WorkbenchPage.java:3159)
at org.eclipse.ui.internal.PartPane.requestActivation(PartPane.java:279)
at org.eclipse.ui.internal.PartPane.handleEvent(PartPane.java:237)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1077)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1058)
at org.eclipse.swt.widgets.Shell.setActiveControl(Shell.java:1447)
at org.eclipse.swt.widgets.Shell.WM_MOUSEACTIVATE(Shell.java:2320)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:4572)
at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:341)
at org.eclipse.swt.widgets.Decorations.windowProc(Decorations.java:1610)
at org.eclipse.swt.widgets.Shell.windowProc(Shell.java:2061)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4985)
at org.eclipse.swt.internal.win32.OS.DefWindowProcW(Native Method)
at org.eclipse.swt.internal.win32.OS.DefWindowProc(OS.java:2526)
at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:80)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:4623)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4985)
at org.eclipse.swt.internal.win32.OS.DefWindowProcW(Native Method)
at org.eclipse.swt.internal.win32.OS.DefWindowProc(OS.java:2526)
at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:80)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:4623)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4985)
at org.eclipse.swt.internal.win32.OS.DefWindowProcW(Native Method)
at org.eclipse.swt.internal.win32.OS.DefWindowProc(OS.java:2526)
at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:80)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:4623)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4985)
at org.eclipse.swt.internal.win32.OS.DefWindowProcW(Native Method)
at org.eclipse.swt.internal.win32.OS.DefWindowProc(OS.java:2526)
at org.eclipse.swt.widgets.Scrollable.callWindowProc(Scrollable.java:80)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:4623)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4985)
at org.eclipse.swt.internal.win32.OS.CallWindowProcW(Native Method)
at org.eclipse.swt.internal.win32.OS.CallWindowProc(OS.java:2425)
at org.eclipse.swt.widgets.Tree.callWindowProc(Tree.java:1533)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:4623)
at org.eclipse.swt.widgets.Tree.windowProc(Tree.java:5937)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4985)
at org.eclipse.swt.internal.win32.OS.PeekMessageW(Native Method)
at org.eclipse.swt.internal.win32.OS.PeekMessage(OS.java:3114)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3749)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2696)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2660)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2494)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:674)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:667)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:123)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
at org.eclipse.equinox.launcher.Main.main(Main.java:1386)
Cannot reproduce in 4DIAC-IDE 1.5.0 RC2 this bug.
Thanks for the update. As I'm also not able to reproduce this bug anymore I will close it for now. I guess that the using Eclipse Kepler helped here.