...

src/calibre/gui2/tweak_book/ui.py

@@ -185,7 +185,10 @@ class CursorPositionWidget(QWidget):  # {{{
         if line is None:
             self.la.setText('')
         else:
+            try:
                 name = unicodedata.name(character, None) if character else None
+            except Exception:
+                name = None
             text = _('Line: {0} : {1}').format(line, col)
             if name:
                 text = name + ' : ' + text