A "Runtime error" is an error in the macro that occurs when trying to load it. It is most most likely caused by the macro not being up-to-date, or your Pythagoras version not being up-to-date.
- Check if your Pythagoras version is up-to-date via Help - Check for updates.
- Restart Pythagoras. This automatically updates the macros.
It is recommended to enable Automatic Updates. This can be done via File - Configure - Automatic update.