Zammad: No Results with Rest Api to search for tickets with state:

[rkopplin]

Infos:

Used Zammad version: 2.0.0
Used Zammad installation source: Ubuntu Package
Operating system: Ubuntu 16.04 on 4 core VServer with 8GB memory.

Expected behavior:
Results for Tickets.

Actual behavior:

API Calls for query with state always without result.
I, [2017-09-13T10:08:04.138566 #9708] INFO -- : Processing by TicketsController#search as HTML
I, [2017-09-13T10:08:04.138671 #9708] INFO -- : Parameters: {"query"=>"state:new"}
I, [2017-09-13T10:08:04.163355 #9708] INFO -- : Completed 200 OK in 25ms (Views: 0.2ms | ActiveRecord: 5.3ms)

Call: api/v1/tickets/search?query=state:new
{"tickets":[],"tickets_count":0,"assets":{}}

Steps to reproduce the behavior:

Query for example for api/v1/tickets/search?query=state:new

Any ideas?
Also tested the example state querys, nothing. everything else works.

[rkopplin]

after using my brain it was clear that the api must use elasticsearch to fetch those values.
fixxed it by setting up elasticsearch.