In mitk\Modules\Bundles\org.mitk.gui.qt.igtexample\src\internal\QmitkIGTExampleView.cpp line 499

QStringList s = QFileDialog::getOpenFileNames(m_Parent,"tool definition file (*.*)",QDir::currentPath(), "open file dialog");

the "open file dialog" should be changed to such as "All Files (*.*)"

or the open file dialog can not select any file.