diff --git a/src/test/java/de/ids_mannheim/korap/test/BaseTest.java b/src/test/java/de/ids_mannheim/korap/test/BaseTest.java
index 560a11e..3fc8726 100644
--- a/src/test/java/de/ids_mannheim/korap/test/BaseTest.java
+++ b/src/test/java/de/ids_mannheim/korap/test/BaseTest.java
@@ -44,13 +44,13 @@
         mockServer.stop();
     }
 
-    protected void createRetrieveResource () throws IOException {
+    protected void createExpectationForRetrieveResource () throws IOException {
         String korapResources = IOUtils.toString(
                 ClassLoader.getSystemResourceAsStream(
                         "korap-api-responses/resources.json"),
                 StandardCharsets.UTF_8);
 
-        mockClient.reset()
+        mockClient
                 .when(request().withMethod("GET").withPath("/resource"))
                 .respond(response()
                         .withHeader(new Header("Content-Type",
@@ -66,7 +66,7 @@
                         "korap-api-responses/" + jsonFilename),
                 StandardCharsets.UTF_8);
 
-        mockClient.reset()
+        mockClient
                 .when(request().withMethod("GET").withPath("/search")
                         .withQueryStringParameter("q", query)
                         .withQueryStringParameter("ql", queryLanguage)
diff --git a/src/test/java/de/ids_mannheim/korap/test/KorapClientTest.java b/src/test/java/de/ids_mannheim/korap/test/KorapClientTest.java
index 30b5ec3..0206da7 100644
--- a/src/test/java/de/ids_mannheim/korap/test/KorapClientTest.java
+++ b/src/test/java/de/ids_mannheim/korap/test/KorapClientTest.java
@@ -13,6 +13,7 @@
 import de.ids_mannheim.korap.sru.KorapResource;
 import de.ids_mannheim.korap.sru.KorapResult;
 import de.ids_mannheim.korap.sru.QueryLanguage;
+import eu.clarin.sru.server.SRUException;
 
 /**
  * The tests are based on the sample corpus from the Goethe corpus.
@@ -29,10 +30,11 @@
         c = new KorapClient("http://localhost:1080", 25, 50);
     }
 
-    @Test
-    public void testCQLQuery () throws HttpResponseException, IOException {
+	@Test
+	public void testCQLQuery ()
+			throws HttpResponseException, IOException, SRUException {
 
-        createExpectationForSearch("der", "cql", "1.2", "50",
+		   createExpectationForSearch("der", "cql", "1.2", "50",
                 "search-der.jsonld");
 
         result = c.query("der", QueryLanguage.CQL, "1.2", 51, 1, null);
@@ -49,8 +51,9 @@
 
     }
 
-    @Test
-    public void testOrQuery () throws HttpResponseException, IOException {
+	@Test
+	public void testOrQuery ()
+			throws HttpResponseException, IOException, SRUException {
 
         createExpectationForSearch("(\"blaue\"|\"grüne\")", "fcsql", "2.0", "0",
                 "search-or.jsonld");
@@ -106,11 +109,14 @@
     @Test
     public void testRetrieveResource ()
             throws HttpResponseException, Exception {
-        createRetrieveResource();
+        createExpectationForRetrieveResource();
         KorapResource[] resources = c.retrieveResources();
         assertEquals(3, resources.length);
-        assertEquals("WPD17", resources[0].getResourceId());
-        assertEquals("WDD17", resources[1].getResourceId());
-        assertEquals("WUD17", resources[2].getResourceId());
+		assertEquals("http://hdl.handle.net/10932/00-03B6-558F-4E10-6201-1",
+				resources[0].getResourceId());
+        assertEquals("http://hdl.handle.net/10932/00-03B6-558F-5EA0-6301-B", 
+        		resources[1].getResourceId());
+        assertEquals("http://hdl.handle.net/10932/00-03B6-558F-6EF0-6401-F", 
+        		resources[2].getResourceId());
     }
 }
diff --git a/src/test/java/de/ids_mannheim/korap/test/KorapSRUTest.java b/src/test/java/de/ids_mannheim/korap/test/KorapSRUTest.java
index ef6511a..d04b0f2 100644
--- a/src/test/java/de/ids_mannheim/korap/test/KorapSRUTest.java
+++ b/src/test/java/de/ids_mannheim/korap/test/KorapSRUTest.java
@@ -40,7 +40,7 @@
                         "korap-api-responses/search-fein.jsonld"),
                 StandardCharsets.UTF_8);
 
-        mockClient.reset()
+        mockClient
                 .when(request().withMethod("GET").withPath("/search")
                         .withQueryStringParameter("q", "fein")
                         .withQueryStringParameter("ql", "cql")
@@ -53,6 +53,27 @@
                                 "application/json; charset=utf-8"))
                         .withBody(searchResult).withStatusCode(200));
     }
+    
+    private void createExpectationForSearchFeinWithUnknownCq () throws IOException {
+        String searchResult = IOUtils.toString(
+                ClassLoader.getSystemResourceAsStream(
+                        "korap-api-responses/search-fein-unknown-cq.jsonld"),
+                StandardCharsets.UTF_8);
+
+        mockClient
+                .when(request().withMethod("GET").withPath("/search")
+                        .withQueryStringParameter("q", "fein")
+                        .withQueryStringParameter("ql", "cql")
+                        .withQueryStringParameter("v", "1.2")
+                        .withQueryStringParameter("context", "sentence")
+                        .withQueryStringParameter("count", "25")
+                        .withQueryStringParameter("offset", "0")
+                        .withQueryStringParameter("cq","corpusSigle=unknown"))
+                .respond(response()
+                        .withHeader(new Header("Content-Type",
+                                "application/json; charset=utf-8"))
+                        .withBody(searchResult).withStatusCode(200));
+    }
 
     private void createExpectationForMatchInfoFein () throws IOException {
         String matchInfoResult = IOUtils.toString(
@@ -124,17 +145,45 @@
     public void searchRetrieveWithResourceId ()
             throws IOException, URISyntaxException, IllegalStateException,
             SAXException, ParserConfigurationException {
-        createExpectationForSearchFein();
+    	createExpectationForRetrieveResource();
+    	createExpectationForSearchFein();
         createExpectationForMatchInfoFein();
 
         ClientResponse response = resource()
                 .queryParam("operation", "searchRetrieve")
                 .queryParam("query", "fein").queryParam("version", "1.2")
-                .queryParam("x-fcs-context", "GOE").get(ClientResponse.class);
+                .queryParam("x-fcs-context", "http://hdl.handle.net/10932/00-03B6-558F-4E10-6201-1").get(ClientResponse.class);
 
         InputStream entity = response.getEntity(InputStream.class);
         checkSearchRetrieveResponseSRUVersion1_2(entity);
     }
+    
+    @Test
+    public void searchRetrieveWithUnknownResourceId ()
+            throws IOException, URISyntaxException, IllegalStateException,
+            SAXException, ParserConfigurationException {
+    	
+    	createExpectationForRetrieveResource();
+    	createExpectationForSearchFeinWithUnknownCq();
+        createExpectationForMatchInfoFein();
+
+        ClientResponse response = resource()
+                .queryParam("operation", "searchRetrieve")
+                .queryParam("query", "fein").queryParam("version", "1.2")
+                .queryParam("x-fcs-context", "unknown").get(ClientResponse.class);
+
+		InputStream entity = response.getEntity(InputStream.class);
+		docBuilder = factory.newDocumentBuilder();
+		Document doc = docBuilder.parse(entity);
+
+		NodeList diagnosticUri = doc.getElementsByTagName("diag:uri");
+		assertEquals("info:srw/diagnostic/1/1",
+				diagnosticUri.item(0).getTextContent());
+
+		NodeList diagnosticMessage = doc.getElementsByTagName("diag:message");
+		assertEquals("Virtual corpus with pid: unknown is not found.",
+				diagnosticMessage.item(0).getTextContent());
+	}
 
     @Test
     public void searchRetrieveFCSQLTest ()
@@ -279,7 +328,7 @@
             throws URISyntaxException, ClientProtocolException, IOException,
             IllegalStateException, SAXException {
 
-        createRetrieveResource();
+        createExpectationForRetrieveResource();
 
         ClientResponse response = resource().queryParam("operation", "explain")
                 .queryParam("x-fcs-endpoint-description", "true")
diff --git a/src/test/resources/korap-api-responses/resources.json b/src/test/resources/korap-api-responses/resources.json
index 64eb69c..929572a 100644
--- a/src/test/resources/korap-api-responses/resources.json
+++ b/src/test/resources/korap-api-responses/resources.json
@@ -1,59 +1,65 @@
 [
-    {
-        "resourceId": "WPD17",
-        "titles": {
-            "de": "Deutsche Wikipedia Artikel 2017",
-            "en": "German Wikipedia Articles 2017"
-        },
-        "description": "A collection of articles of German Wikipedia from July 1st, 2017.",
-        "languages": ["deu"],
-        "layers": {
-            "18": "marmot/m",
-            "19": "marmot/p",
-            "23": "opennlp/p",
-            "11": "corenlp/p",
-            "27": "tt/l",
-            "28": "tt/p"
-        },
-         "institution" : "Wikimedia Foundation",
-         "landingPage" : "https://korap.ids-mannheim.de?corpusSigle=WPD17"
+  {
+    "resourceId": "http://hdl.handle.net/10932/00-03B6-558F-4E10-6201-1",
+    "titles": {
+      "de": "Deutsche Wikipedia Artikel 2017",
+      "en": "German Wikipedia Articles 2017"
     },
-    {
-        "resourceId": "WDD17",
-        "titles": {
-            "de": "Deutsche Wikipedia-Diskussionskorpus 2017",
-            "en": "German Wikipedia talk corpus 2017"
-        },
-        "description": "A collection of talk pages of German Wikipedia from July 1st, 2017.",
-        "languages": ["deu"],
-        "layers": {
-            "18": "marmot/m",
-            "19": "marmot/p",
-            "23": "opennlp/p",
-            "11": "corenlp/p",
-            "27": "tt/l",
-            "28": "tt/p"
-        },
-        "institution" : "Wikimedia Foundation",
-         "landingPage" : "https://korap.ids-mannheim.de?corpusSigle=WDD17"
+    "description": "A collection of articles of German Wikipedia from July 1st, 2017.",
+    "languages": [
+      "deu"
+    ],
+    "layers": {
+      "1": "opennlp/p",
+      "14": "marmot/m",
+      "15": "marmot/p",
+      "29": "corenlp/p",
+      "30": "tt/l",
+      "31": "tt/p"
     },
-    {
-        "resourceId": "WUD17",
-        "titles": {
-            "de": "Deutsche Wikipedia-Benutzerdiskussionskorpus 2017",
-            "en": "German Wikipedia talk corpus 2017"
-        },
-        "description": "A collection of user talk pages of German Wikipedia from July 1st, 2017.",
-        "languages": ["deu"],
-        "layers": {
-            "18": "marmot/m",
-            "19": "marmot/p",
-            "23": "opennlp/p",
-            "11": "corenlp/p",
-            "27": "tt/l",
-            "28": "tt/p"
-        },
-        "institution" : "Wikimedia Foundation",
-         "landingPage" : "https://korap.ids-mannheim.de?corpusSigle=WUD17"
-    }
+    "institution": "IDS Mannheim",
+    "landingPage": "https://korap.ids-mannheim.de?cq=corpusSigle=WPD17"
+  },
+  {
+    "resourceId": "http://hdl.handle.net/10932/00-03B6-558F-5EA0-6301-B",
+    "titles": {
+      "de": "Deutsche Wikipedia-Diskussionskorpus 2017",
+      "en": "German Wikipedia talk corpus 2017"
+    },
+    "description": "A collection of talk pages of German Wikipedia from July 1st, 2017.",
+    "languages": [
+      "deu"
+    ],
+    "layers": {
+      "1": "opennlp/p",
+      "14": "marmot/m",
+      "15": "marmot/p",
+      "29": "corenlp/p",
+      "30": "tt/l",
+      "31": "tt/p"
+    },
+    "institution": "IDS Mannheim",
+    "landingPage": "https://korap.ids-mannheim.de?cq=corpusSigle=WDD17"
+  },
+  {
+    "resourceId": "http://hdl.handle.net/10932/00-03B6-558F-6EF0-6401-F",
+    "titles": {
+      "de": "Deutsche Wikipedia-Benutzerdiskussionskorpus 2017",
+      "en": "German Wikipedia user talk corpus 2017"
+    },
+    "description": "A collection of user talk pages of German Wikipedia from July 1st, 2017.",
+    "languages": [
+      "deu"
+    ],
+    "layers": {
+      "1": "opennlp/p",
+      "14": "marmot/m",
+      "15": "marmot/p",
+      "29": "corenlp/p",
+      "30": "tt/l",
+      "31": "tt/p"
+    },
+    "institution": "IDS Mannheim",
+    "landingPage": "https://korap.ids-mannheim.de?cq=corpusSigle=WUD17"
+  }
 ]
\ No newline at end of file
diff --git a/src/test/resources/korap-api-responses/search-fein-unknown-cq.jsonld b/src/test/resources/korap-api-responses/search-fein-unknown-cq.jsonld
new file mode 100644
index 0000000..f886d50
--- /dev/null
+++ b/src/test/resources/korap-api-responses/search-fein-unknown-cq.jsonld
@@ -0,0 +1,95 @@
+{
+  "@context": "http://korap.ids-mannheim.de/ns/KoralQuery/v0.3/context.jsonld",
+  "meta": {
+    "count": 25,
+    "startIndex": 0,
+    "timeout": 10000,
+    "context": {
+      "left": [
+        "token",
+        6
+      ],
+      "right": [
+        "token",
+        6
+      ]
+    },
+    "fields": [
+      "ID",
+      "UID",
+      "textSigle",
+      "corpusID",
+      "author",
+      "title",
+      "subTitle",
+      "textClass",
+      "pubPlace",
+      "pubDate",
+      "availability",
+      "layerInfos",
+      "docSigle",
+      "corpusSigle"
+    ],
+    "version": "0.63.3",
+    "benchmark": "0.19016714 s",
+    "totalResources": 0,
+    "totalResults": 0,
+    "serialQuery": "tokens:s:ich",
+    "itemsPerPage": 25
+  },
+  "query": {
+    "@type": "koral:token",
+    "wrap": {
+      "@type": "koral:term",
+      "match": "match:eq",
+      "layer": "orth",
+      "key": "ich",
+      "foundry": "opennlp",
+      "rewrites": [
+        {
+          "@type": "koral:rewrite",
+          "src": "Kustvakt",
+          "editor": "Kustvakt",
+          "operation": "operation:injection",
+          "scope": "foundry",
+          "_comment": "Default foundry has been added."
+        }
+      ]
+    }
+  },
+  "collection": {
+    "@type": "koral:docGroup",
+    "operation": "operation:and",
+    "operands": [
+      {
+        "@type": "koral:doc",
+        "match": "match:eq",
+        "type": "type:regex",
+        "value": "CC.*",
+        "key": "availability"
+      },
+      {
+        "@type": "koral:doc",
+        "match": "match:eq",
+        "value": "unknown",
+        "key": "corpusSigle"
+      }
+    ],
+    "rewrites": [
+      {
+        "@type": "koral:rewrite",
+        "src": "Kustvakt",
+        "editor": "Kustvakt",
+        "operation": "operation:override",
+        "original": {
+          "@type": "koral:doc",
+          "match": "match:eq",
+          "value": "unknown",
+          "key": "corpusSigle"
+        },
+        "_comment": "Free corpus access policy has been added."
+      }
+    ]
+  },
+  "matches": []
+}
\ No newline at end of file