Error message 'Expired Certificates'

On Windows PCs:

• Download certificate ISRG X1 from https://letsencrypt.org/certificates/
• The certficate that needs to be downloaded is the Self-signed, Pem
• Open Internet Explorer -- tools -- Internet options
• Content -- Certificates
• Third Party Root Certification Authorities -- Import
• Select the ISRG X1 certificate
• Add all certificates to Third Party Root Certification Authorities
• Install certificate, click on \"yes\" and close.

On macOS, iOS

Go to this website: https://letsencrypt.org/certificates/

Download the certificate ISRG X1 and install it on Safari.

If this doesn't work, do this:

• In the Safari app, click Safari and Preferences
• Click the Privacy tab
• Click the Manage Web Site Data button
• A new window will open and you will see a list of websites that stored data.
• Find the affected site (Freepik.com), you can use the Search field to find easily.
• Select the domain
• And click the Remove button
• And click done.

For further information, you can check this article: https://community.letsencrypt.org/t/os-x-10-11-clients-not-connecting-to-site-with-lets-encrypt-certificates/161576/12

Also, here you can check if the certificate is compatible with your OS: https://letsencrypt.org/docs/certificate-compatibility/#platforms-that-trust-isrg-root-x1