A question: you said that today you got this message. Have you installed Zurich today for the first time, or it used to work before, and you are only getting this message today ?
Try the following:
- Uninstall the Addon Manager from Windows Control Panel-
- Uninstall Zurich from Windows Control Panel, and (important) reply YES to the question about removing the Addon Manager. This will entirely remove everything from FSX
- To be absolutely sure you have the latest version of the installer, download Zurich again and install it.
If you follow all these steps to the letter, the software is guaranteed to work. If not, it must be something else in conflict, that's why I've asked you if it used to work before, to know if you have installed something else that might have caused the problem.