For example "content-privacy" is not setted on a project site.
As result, on BO side there is JS error such as:
Entry.js:139 2021-02-15T16:25:07.289Z ERROR [Ametys.message.MessageBus] Un composant a rencontré une exception lors du traitement d'un message du bus (TypeError: Cannot read property 'id' of null) TypeError: Cannot read property 'id' of null at constructor._getStatusCb (SmartContentController.js:266) at constructor.callParent (ext-all.js:13647) at constructor._getStatusCb (ContentPrivacyController.js:116) at constructor._getStatus (SmartContentController.js:74) at constructor.updateState (SmartContentController.js:63) at constructor.refresh (CommonController.js:1067) at constructor._onSelectionChanged (CommonController.js:1033) at constructor.fire (MessageBus.js:170) at constructor.cb (MessageMethods.js:153)
This occurs because site.getValue('content-privacy') returns null.