Support Wissensdatenbank

free Let’s Encrypt SSL certificate does not work

When you open the protected website, do you get a message that the website is not private? Or the message “This is not a secure connection”, “NET::ERR_CERT_AUTHORITY_INVALID”.

This is because as of 2015 Lets Encrypt has a new root certificate and the old one expired as of 9/30/2021. All computers that have not been updated since 2015 will no longer know the new certificates from Let’s Encrypt and will now receive an error message. This affects millions of websites that your old computer can no longer open.

Translated with www.DeepL.com/Translator (free version)

1. open the website https://letsencrypt.org does the error message also appear here?
2. Please check your computer and install all the latest updates. Follow the manufacturer’s instructions for your device. Alternatively, we offer you the option of using a paid SSL certificate. Click here. However, you will not be able to open millions of websites.

The following system requirements must be met so that you can open websites with the free SSL certificate without error messages:

• Windows >= XP SP3 (provided that the automatic root certificate update is not manually deactivated)
• macOS >= 10.12.1
• iOS >= 10 (iOS 9 does not include it)
• iPhone 5 and above can upgrade to iOS 10 and can thus trust ISRG Root X1
• Android >= 7.1.1 (but Android >= 2.3.6 will work by default due to our special cross-sign)
• Mozilla Firefox >= 50.0
• Ubuntu >= xenial / 16.04 (with updates applied)
• Debian >= jessie / 8 (with updates applied)
• Java 8 >= 8u141
• Java 7 >= 7u151
• NSS >= 3.26