...and this leads to a JS error

HTR:

1. Create an instance of the new search service
2. In criteria page, Select "Content > Site" and "the value" and select a site
3. Save
4. Try to edit the service. You get this JS error:

   ERROR	[Ametys.data.ServerComm]	Une erreur est survenue dans le traitement de la réponse serveur (TypeError: Cannot read property 'isEmptyStore' of null)
    TypeError: Cannot read property 'isEmptyStore' of null
       at constructor.setValue (Ext.enhancements.js:2120)
       at constructor.callback (Ext.enhancements.js:2155)
       at constructor.triggerCallbacks (ext-all.js:88028)
       at constructor.setCompleted (ext-all.js:87988)
       at constructor.setSuccessful (ext-all.js:88002)
       at constructor.process (ext-all.js:87900)
       at constructor.processResponse (ext-all.js:97681)
       at constructor.createRequestCallback (ServerCommProxy.js:284)
       at constructor.<anonymous> (ServerComm.js:862)
       at Array.forEach (<anonymous>)