Can't accept invite to space

[kittykat]

Description

When trying to accept a space invite, it fails with a "Failed to join room. You are not allowed to join this room." error. The specific space that this is happening for is !aDwXHWxCimolPLadup:matrix.org

I've tried accepting the invite at e.g. 2022-03-28 09:22:40 UTC

Steps to reproduce

Not sure what the cause is, but this is what happened in this case:

1. User1 invited user2 to a space
2. User2 tried to accept invite 1-2+ weeks later
3. User2 sees "Failed to join room" error
4. If user1 tries to invite user2 to the space again, user1 sees a "User @user2:server is already invited to the room" error

Version information

• Homeserver: matrix.org (both users and the space are on there)

[anoadragon453]

From what I can see from matrix.orgs database, the m.room.join_rules state event of the room has a join rule of private set - which doesn't currently mean anything. This may be why users are having trouble joining, even if they have an invite. Do you know how the room may have gotten into this state?

[kittykat]

I was testing spaces on iOS at the time and I didn't do anything odd that I can think of 🤔

@gileluard - do you know why "private" may have been set?

[gileluard]

@anoadragon453 @kittykat we use a preset public or private but this may be a mistake. What should be the join_rules for private spaces?

[gileluard]

Not that I tried to reproduce this bug with my local synapse and everything's fine.

[gileluard]

@kittykat I may have found the issue. The new Room Access screen sets the m.room.join_rules to private instead of invite I believe.

[anoadragon453]

@gileluard That sounds like a likely cause. I'm going to close this issue on the assumption that this was the issue.

@kittykat note that the original space's join rule can be fixed by toggling the Visibility settings in Element Web. Or just edit the m.room.join_rules state event manually in devtools.