SSL suddenly stopped working

[KangJL]

@vitanova

but this browser complains about the certificate chain (SEC_ERROR_UNKNOWN_ISSUER)

This?

Warning: "The certificate is not trusted in all web browsers"

If you have installed an SSL certificate on InfinityFree, you may want to use an SSL Checker tool to verify your SSL certificate was installed correctly. However, when doing so, you see an error like this: The certificate is not trusted in all web browsers. You may need to install an Intermediate/chain certificate to link it to a trusted root certificate. Learn more about this error. The fastest way to fix this problem is to contact your SSL provider. What does this warning mean for your sit…

@vitanova

What can I do about this?

Use VPN?