Print a warning exception on unsupportedmizfiles

Author: karel26

core/mizfile.py

@@ -52,6 +52,7 @@ def _load(self):
                 except FileNotFoundError:
                     pass
         except Exception:
+            self.log.warning(exc_info=True)
             raise UnsupportedMizFileException(self.filename)
 
     def save(self, new_filename: Optional[str] = None):