If I try to save the URL
https://www.uni-ms.de/de/ using the Wayback Machine (archive.org), I get the following response:
However, the site is perfectly fine, and I haven’t been able to find anything strange in the HTTPS certificates or HTTP response headers, either: https://www.uni-ms.de/de/. Saving the HTTP version http://www.uni-ms.de/de/ works without issues, too. What’s the problem here?