Fix fatal call on logger

threads/MainThread.py

@@ -54,7 +54,7 @@ class MainThread():
     def _log(self, tag, msg):
         self.ui.consoleView.setText("{} {}\n{}".format(tag, msg, self.ui.consoleView.text()))
         if "FATAL" in tag:
-            _fatal(msg)
+            self._fatal(msg)
 
     def _playPause(self):
         if self.graph.running: