Clideo website won't open on macOS <= 10.11 (El Capitan and older)

On Sept 30th, 2021, the root certificate DST Root CA X3 from Let's Encrypts expired. It has been replaced with the ISRG Root X1 certificate. 

If you cannot open https://clideo.com or other websites on 10.11 or older macOS, you might need to update to a newer macOS version or install the trusted root certificate yourself.

Install the trusted root certificate on macOS

For older macOS (10.11 (El Capitan and older)), do the following:

1. Go to http://x1.i.lencr.org/ to download the ISRG Root X1 certificate file.
2. Open the Keychain Access app and drag the certificate file into the System folder of that app.
3. In System, double click ISRG Root X1 certificate, select Trust and change Use System Defaults to Always Trust. Close the app and confirm the change with your password (if prompted).