Soft crash after clicking a room on a room list and getting a "!abc:def not found in roomsMap" error

[Half-Shot]

Steps to reproduce

1. Have been using the client for a few hours.
2. Click on a room in the room list.

Outcome

What did you expect?

Client to open the room

What happened instead?

Client exploded with a React soft crash:

Error: Room !abcdef:example.org not found in roomsMap
    at RoomListViewViewModel.getRoomItemViewModel (vector://vector/webapp/bundles/f265129f4a07af0f65a5/element-web-app.js:17975:15)
    at vector://vector/webapp/bundles/f265129f4a07af0f65a5/init.js:109969:32
    at vector://vector/webapp/bundles/f265129f4a07af0f65a5/init.js:109916:18
    at vector://vector/webapp/bundles/f265129f4a07af0f65a5/7781.js:114314:53
    at Array.map (<anonymous>)
    at vector://vector/webapp/bundles/f265129f4a07af0f65a5/7781.js:114279:44
    at renderWithHooks (vector://vector/webapp/bundles/f265129f4a07af0f65a5/7781.js:69177:21)
    at updateFunctionComponent (vector://vector/webapp/bundles/f265129f4a07af0f65a5/7781.js:71323:15)
    at updateSimpleMemoComponent (vector://vector/webapp/bundles/f265129f4a07af0f65a5/7781.js:71063:10)
    at beginWork (vector://vector/webapp/bundles/f265129f4a07af0f65a5/7781.js:72618:14)`

Operating system

Arch Linux

Application version

Element Nightly version: 2026030101

How did you install the app?

AUR

Homeserver

Synapse

Will you send logs?

Yes

[Half-Shot]

This is reproducible (with difficulty) by scrolling the room list very quickly and clicking on an entry.

[t3chguy]

Affects prod as per the dup