Messages get completely stuck at "Encrypting your message"

[richvdh]

Note: this is distinct from #15476, in which messages are slow to send but do get sent eventually.

There is a bug in which sometimes the encryption process gets completely stuck, with messages staying in the "encrypting" state for 15 minutes or more.

[richvdh]

Looking at a recent rageshake which exhibits this (https://github.com/matrix-org/element-web-rageshakes/issues/19899), it seems like we've got stuck trying to make an Olm session for a particular device, and all attempts at encryption for this device are then blocking. Unfortunately the logs don't seem to go back far enough to show it getting stuck.

The code which manages this is in olmlib.ensureOlmSessionsForDevices. It looks robust, but it's also really quite complex and it's hard to be certain that it is robust.

Ideally, we would refactor it so that we can be more certain that it will catch all the error cases, but that's a non-trivial amount of work, and we're going to replace this bit of code for #21972.

I'd still be interested in rageshakes from anyone seeing this behaviour, as they might point towards a quick fix.

[davidegirardi]

I restarted Element Desktop Nightly and the 2 stuck messages disappeared, while the UTDs are now decrypted with a grey shield.

[uhoreg]

FWIW, the first time I encountered this issue in a rageshake was shortly after matrix-org/matrix-js-sdk#3035 landed, which looks like it might touch some relevant code, but I didn't see anything in that PR that looked like it could cause this breakage. I don't remember seeing any reports of this before that time, so it seems to be a recent issue.

[golam71]

so as of now all of my messages stay on this state so far even after waiting a hour and re trying i am not been able to send a single message
this issue is from 2023 a year has passed so what now ?
if i cant even send any message whats the point of using it then?
is there even any walkaround for it?

[richvdh]

The rust cryptography stack will resolve this issue.

[richvdh]

(To use the rust cryptography stack, assuming you are on a recent version of Element, log out and in again.)