Receiving "Unable to decrypt message" for several users in specific rooms

[zenimasu]

Steps to reproduce

Initially reached out via email communication (NVT#1560598) and was requested to leave a GitHub issue. Several users are seeing "Unable to decrypt message" in encrypted rooms for specific users, but not all users are unable to see the messages. I'll send logs from my account (the one who can't read the message) and the sender's account. The messages are still showing up as "Unable to decrypt message" if that helps.

Outcome

What did you expect?

To be able to see all messages in the room

What happened instead?

"Unable to decrypt message" is shown instead of the message

Operating system

No response

Application version

No response

How did you install the app?

No response

Homeserver

No response

Will you send logs?

Yes

[zenimasu]

logs were sent from both users just now

[BillCarsonFr]

logs were sent from both users just now

Hello, it looks like the logs we have from the sender are from the wrong device. We need the logs from the device that sent the message that cannot be decrypted.

Is it possible to check on your side?

[BillCarsonFr]

Looks several messages coming from justm**son:t**.ems.host are not decryptable on purpose. The sender has disabled sending keys to unverified devices. You might want to check with him he enabled this option in settings:

If not please confirm

[zenimasu]

@BillCarsonFr could you reattach the image? For some reason I'm unable to see it (it just looks like a broken image).

[zenimasu]

Looks several messages coming from justm**son:t**.ems.host are not decryptable on purpose. The sender has disabled sending keys to unverified devices. You might want to check with him he enabled this option in settings:

If not please confirm

I had that user toggle the setting in Security & Privacy for Never send encrypted messages to unverified sessions from this session to off and it looks like we can see their messages now. I'm still unable to see the image from the earlier reply from @BillCarsonFr, so if this was not the change you were suggesting, please let me know.

[richvdh]

That's the correct toggle, yes. I'm glad it has resolved the issue with that user.

As @BillCarsonFr said earlier, although we have debug logs from @david:t**.ems.host, they don't appear to be from the device that sent the undecryptable message, so we're not able to action this further.

If you're still encountering problems, please send a new pair of debug logs, from both sides of the conversation.