Free SSL It's Not Working Properly

Why the new version of SSL Certificate (ISRG Root X1) has a problem with the old versions of Android (4.4 and less version) and the website encounters an error » (NET::ERR_CERT_INVALID). recently my website traffic has dropped dramatically.

Hi @hassi and welcome to the LE community forum :slight_smile:

Because for a root cert to be trusted, it has to be in the trusted root store.
The Andriod 4.4 and less were issued their trust stores before the root cert ("ISRG Root X1") was issued (June 4, 2015).
So it is unknown to them and thus untrusted.
As the older Androids are no longer receiving any support, their trust stores are becoming outdated and are not being synchronized with any changes since then.

You could try staving off the inevitable by switching to another (free) CA that does have access to an older trusted root cert.

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.