Bug 117925 [Intro] Misleading exception message in WelcomeEditor.init()
... it says it expects an IFileEditorInput, but it actually checks for WelcomeEditorInput. Suggested patch appended.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/WelcomeEditor.java
offset = text.getOffsetAtLocation(new Point(e.x, e.y));
                } catch (IllegalArgumentException ex) {
                    
                }
                if (offset == -1)
                    text.setCursor(null);
                else if (item.isLinkAt(offset))
                    text.setCursor(handCursor);
                else
                    text.setCursor(null);
            }
        });
        styledText.addTraverseListener(new TraverseListener() {
            public void keyTraversed(TraverseEvent e) {
                StyledText text = (StyledText) e.widget;
                switch (e.detail) {
                case SWT.TRAVERSE_ESCAPE:
                    e.doit = true;
                    break;
                case SWT.TRAVERSE_TAB_NEXT:
                    
                    if ((e.stateMask & SWT.CTRL) != 0) {
                        if (e.widget == lastText)
                            return;
                        else {
                            e.doit = false;
                            nextTabAbortTraversal = true;
                            lastText.traverse(SWT.TRAVERSE_TAB_NEXT);
                            return;
                        }