Android Client cannot verify letsencrypt certificate


Hello all,

I have my seafile server running now since a couple of months. I used certbot to integrate a letsencrypt certificate. It works fine in LAN and WAN on multiple devices. Yet I have one Android Phone in the field that suddenly got a certificate issue. It says not trusted connection and cannot verify the issuer, the fingerprint and timestamp at all. I’ve tried clearing cache and data, reinstalling, LTE vs Wlan, checked AV settings with other devices that work and also imported the certificate manually. The user has no issue with her other devices (windows and iOS)
Her security settings on her Android are also the same as mine. I don’t know what to do anymore and need assistance. Since all other devices work fine I’m sure it’s a issue on that phone. Any ideas?
Kind regards


Does other Let’s Encrypt sites work? (Like Otherwise try to renew the Cert and Chrome.


The User can use Firefox and Chrome on that device and goto the Server-URL without any issues. Its only the Seafile App on that Android that is having this issue


Have tried a older/newer version?


its the Version installed from the Playstore yesterday 2.11 somthing.


Try an older version:


I tested:


no difference


Importing Certs doesn’t work for the android client for a long time now. Which Android Version. Is there a old “shitty” internal browser and if yes does it accept the cert?


It’s a Android 8.1 device and it’s up2date from an app perspective


Okay so I finally got this solved:

I needed to add: DHE-RSA-AES128-SHA for this Android device to work. (its a honor 8) not so old but still seams to rely on that cipher.

just wanted to let you know