Element/Riot Chat: Fix “Waiting for this message, this may take a while”

Encryption in Element (via the Matrix protocol) works flawlessly. Most of the times. When it doesn’t, it can be quite annoying.
In this particular case, I had the issue that I was able to receive and send messages in a chat without any problems, however, the other person always had to wait pretty long for messages/didn’t work at all sometimes.

It only showed a message: Waiting for this message, this may take a while.

If this or something similar happens, try issuing the command /discardsession on the web app/Desktop interface on the client where sending/receiving still works. This fixed the problem for any future messages for me.

Source: Github Issues for element-android #1721 – reply by @kat-co: https://github.com/vector-im/element-android/issues/1721#issuecomment-880214682