Let's Encrypt Authority X3 - not recognized anywhere with Samsung Internet and Chrome on Android 9

Hi guys,

I’ve been having significant difficulties with Let’s encrypt certificates on my Android phone during the past couple of days. I’m running Android 9 on a Samsung A50 device. Any website with a Let’s Encrypt Authority X3 certificate that I try to enter is considered not secure by both Samsung Internet and Chrome browsers (including this very community forum btw). I’ve noticed that apps started crashing too.
After excessive googling, I still have no solution to this issue from a user standpoint.
Any ideas on how to fix this?


I ran this command: entered any website with a Let’s encrypt certificate

It produced this output: the certificate is not trusted by the device

It’s weird that it would affect multiple browsers, because Chrome on Android ships its own root certificates.

Can I ask what ISP and country you are visiting these sites from?

Is the date and time on the device definitely correct?

On the Chrome “Your connection is not private” screen, what is the error code? For example, NET::ERR_CERT_AUTHORITY_INVALID. Or perhaps NET::ERR_CERT_COMMON_NAME_INVALID.

Are you able to visit https://www.identrustssl.com successfully?

I’ve tried different ISPs, two Wi-Fi networks at home and at work plus Vodafone, my mobile data provider. It doesn’t affect the problem at all. I’m visiting from the Czech republic, from Prague.

Date and time should definitely be fine since I’ve tried both automatic and manual entries.


I’m able to visit the web you’ve mentioned without a problem.

Dne pá 14. 6. 2019 1:29 uživatel _az via Let’s Encrypt Community Support letsencrypt@discoursemail.com napsal:

Ok, I’ve found the solution, hope this helps some future users.

This particular certificate was turned off for some reason. The only change done to the phone within the last days was a corporate Microsoft Outlook installed on the device along with some other Microsoft corporate apps.

Switching the certificate on fixed the issue.

Dne pá 14. 6. 2019 6:41 uživatel Artur Galstyan artur.gal.ag@gmail.com napsal: