# Error when trying to update the watchlist for a group via API (PUT groups/{id}.json)

**URL:** <https://meta.discourse.org/t/error-when-trying-to-update-the-watchlist-for-a-group-via-api-put-groups-id-json/393572>\
**Category:** Bug\
**Tags:** groups, rest-api\
**Created:** [January 15, 2026, 6:19pm UTC](https://meta.discourse.org/t/error-when-trying-to-update-the-watchlist-for-a-group-via-api-put-groups-id-json/393572 "2026-01-15T18:19:44Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![zogstrip](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/zogstrip/32/512781_2.png) [@zogstrip](https://meta.discourse.org/u/zogstrip)\
**Post date:** [January 16, 2026, 8:21pm UTC](https://meta.discourse.org/t/error-when-trying-to-update-the-watchlist-for-a-group-via-api-put-groups-id-json/393572/5 "2026-01-16T20:21:29Z")

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> [@apf](#):
>
> I have already tried to add `"update_existing_users”=True` in the json data of the PUT call, the error was the same as reported. ☹

It [expects](https://github.com/discourse/discourse/blob/d50d6f797fb0695a3b9784b8fa97d0a00caadcd4/app/controllers/groups_controller.rb#L180) the string “true” - lowercase.

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_[View the full topic](https://meta.discourse.org/t/error-when-trying-to-update-the-watchlist-for-a-group-via-api-put-groups-id-json/393572)._