diff --git a/openbis/source/java/ch/systemsx/cisd/openbis/generic/client/web/client/application/ui/experiment/ProjectSelectionTreeGridContainer.java b/openbis/source/java/ch/systemsx/cisd/openbis/generic/client/web/client/application/ui/experiment/ProjectSelectionTreeGridContainer.java
index da8219537a4b0597e05bbf06cb1ab87714f17578..82217fe0e3d1e563cbf4e95fe7b3d771acff9379 100644
--- a/openbis/source/java/ch/systemsx/cisd/openbis/generic/client/web/client/application/ui/experiment/ProjectSelectionTreeGridContainer.java
+++ b/openbis/source/java/ch/systemsx/cisd/openbis/generic/client/web/client/application/ui/experiment/ProjectSelectionTreeGridContainer.java
@@ -259,7 +259,7 @@ public final class ProjectSelectionTreeGridContainer extends LayoutContainer imp
                             case Event.ONMOUSEOUT:
                                 // Only fire the mouse out event if it's leaving this
                                 // widget.
-                                Element related = event.getRelatedTarget();
+                                Element related = event != null ? event.getRelatedTarget() : null;
                                 if (related != null && getElement().isOrHasChild(related))
                                 {
                                     return;
@@ -277,6 +277,8 @@ public final class ProjectSelectionTreeGridContainer extends LayoutContainer imp
                 }
 
             });
+        columnConfig.setMenuDisabled(true);
+        columnConfig.setSortable(true);
         return columnConfig;
     }