Error message for invalid m.room.encryption event is very bad

[tulir]

Description

When sending a message to a room that contains a m.room.encryption event that riot can't handle (e.g. redacted, sent incorrectly, etc), riot shows an extremely unhelpful "Your message was not sent" notification. The notification contains absolutely no information why it was not sent, and it offers a "Resend message" button that doesn't work.

Steps to reproduce

• Send a m.room.encryption state event with an unsupported algorithm or redact an existing m.room.encryption event
• Try to send a message

Expected result: useful error message that says the room is misconfigured or that the server is hiding the configuration, maybe offer a button to send a fixed encryption event if the user is admin.

Actual result: useless and confusing error message

This might also apply for

Version information

• Platform: web
• Browser: Firefox 79.0b2
• OS: Ubuntu 20.04
• URL: riot.im/develop

[t3chguy]

Duplicate of https://github.com/vector-im/riot-web/issues/3498#issuecomment-288840814