When I try to search in shared documents, I receive the following error:

Code:
Fehler im Netzwerkdienst

method:	SearchRequest
msg:	system failure: Caught null
code:	service.FAILURE
detail:	soap:Receiver
trace:	btpool0-98:1244576002652:b869f28f2581bbb9
request:	

Body: {
  SearchRequest: {
    _jsns: "urn:zimbraMail",
    limit: 100,
    locale: {
      _content: "de"
     },
    offset: 0,
    query: "zimbra (inid:20681 OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12385" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12386" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:14479" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:46693" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:47677" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12388" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12387" OR inid:19245 OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:16502" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12231" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12227" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:13419" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:13415" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12232" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:11061" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12226" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:13421" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:45901" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:49696" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:44389" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12230" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12228" OR inid:20681 OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12385" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12386" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:14479" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:46693" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:47677" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12388" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12387" OR inid:19245 OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:16502" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12231" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12227" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:13419" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:13415" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12232" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:11061" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12226" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:13421" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:45901" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:49696" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:44389" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12230" OR inid:"89592b56-cbe8-44b4-ba45-441753c65814:12228" OR is:local)",
    types: "wiki,document",
    tz: {
      id: "(GMT+01.00) Amsterdam / Berlin / Bern / Rome / Stockholm / Vienna"
     }
   }
 },
Header: {
  context: {
    _jsns: "urn:zimbra",
    account: {
      _content: "rgustavik@wien.info",
      by: "name"
     },
    authToken: "(removed)",
    format: {
      type: "js"
     },
    notify: {
      seq: 5
     },
    sessionId: {
      _content: 1491,
      id: 1491
     },
    userAgent: {
      name: "ZimbraWebClient - FF3.0 (Linux)",
      version: "5.0.16_GA_2921.RHEL5_64"
     }
   }
 }
This happens, when I check the Option to include shared Folders and do not specify a folder in: or under:
This doesn't happen, when I uncheck the Option
Any Ideas?