We should address this after the messaging has been finalized in T402172

The translation for notloggedin exists but is being passed in raw in here
https://github.com/wikimedia/mediawiki-extensions-ReadingLists/blob/master/resources/ext.readingLists.bookmark/bookmark.js#L138

Current:

mw.notify(
						mw.msg( 'readinglists-browser-error-intro', err ),
						{ tag: 'saved', type: 'error' }
					);

Expected:

mw.notify(
						mw.msg( 'readinglists-browser-error-intro', mw.msg( err ) ),
						{ tag: 'saved', type: 'error' }
					);

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hello this is my change id on gerrit
https://gerrit.wikimedia.org/r/c/mediawiki/extensions/ReadingLists/+/1183226

Change #1183226 had a related patch set uploaded (by Jdlrobson; author: LazyShrey):

[mediawiki/extensions/ReadingLists@master] ReadingLists: localize browser error message

https://gerrit.wikimedia.org/r/1183226

Change #1183226 had a related patch set uploaded (by LazyShrey; author: LazyShrey):

[mediawiki/extensions/ReadingLists@master] Localize browser error message

https://gerrit.wikimedia.org/r/1183226

Change #1183226 merged by jenkins-bot:

[mediawiki/extensions/ReadingLists@master] Localize browser error message

https://gerrit.wikimedia.org/r/1183226

@Sneha The following messages are used here:

* readinglists-browser-error-intro
* readinglists-db-error-list-entry-deleted

From i18n/qqq.json

"readinglists-browser-error-intro": "Message indicating that an error has occurred\n\nParameters:\n* $1 - The error message from the server.",
"readinglists-db-error-list-entry-deleted": "Error message used when trying to do something with a list entry that has been deleted.",

From i18n/en.json

"readinglists-browser-error-intro": "An error has occurred: $1",
"readinglists-db-error-list-entry-deleted": "List entry $1 has been deleted.",

Test Result - Beta

Status: ✅ PASS
Environment: beta
OS: macOS Sequoia 15.5
Browser: Chrome Canary (latest as of test date)
Device: MS
Emulated Device: NA

Test Case 1: Session timeout error message localization

1. Log in and open two tabs of the same wiki page.
2. In Tab 1, log out.
3. In Tab 2, click the Reading List (bookmark) icon.
4. ✅ AC1: A notification appears with a localized, human-readable error message.
5. ✅ AC2: The raw error code “notloggedin” does not appear.

This seems pretty clear cut so I added the verified tag. If it doesn't get resolved please remove the verified tag.