Sync error with Joplin Cloud and Android App: "Trust anchor for certification path not found"

Hello there, Joplin community. This is my first time posting a support request. I hope I'm getting it right.


I have been loving Joplin for a year or so (thanks, Laurent), and have just recently decided to buy a Joplin Cloud subscription, mostly to give something back. My notes were originally created on my Ubuntu laptop. I have only recently installed the Android app.

Desired Behaviour

I am trying to sync both my Ubuntu laptop and my Android tablet with my Joplin Cloud database, so that the notes I have on my laptop can be accessed on the tablet.


My laptop syncs fine, from what I can tell. The Android tablet, however, returns the following error message from the Joplin server, and fails to download any of my notes:

JoplinServerApi: ""Error: uploadBlob: PUT Error: Trust anchor for certification path not found.

I attach the relevant logs below.


I am using Joplin 2.6.8 on Android 7 (Kernel 3.10.84-14953299).

Here is the export of the debugging log:

syncReport-1640763043646.txt (131.7 KB)

Encryption is not enabled on the laptop. On the Android end, "Fail-safe" and "Ignore TLS Certificate" are enabled. The sync configuration check is successful.

Any suggestion of what might be causing the problem? Am I using too old a version of Android?

Cheers, and let me know if I omitted any crucial information.

-- Mu

Hmm I think that's the Let's Encrypt issue - Fix for "Certificate has expired" error with Joplin Cloud and self-hosted sync targets

It has been fixed but I think it still affects older platforms, which are missing some certificate. I'm not sure at this point how to fix this, especially if you've already tried to disable ssl checks.

(thanks for the quick response)

Ack--I see. So you think that upgrading to a more recent version of Android should fix the issue automatically?

I think it may be possible to install updated root certificate on your Android.

Thanks Roman for the tip--I'm looking into it. I'll report back with the results.

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