diff --git a/.classpath b/.classpath
index 9721b6604..f507f08c4 100644
--- a/.classpath
+++ b/.classpath
@@ -65,26 +65,26 @@
 	<classpathentry kind="lib" path="lib/httpclient-4.5.2.jar"/>
 	<classpathentry kind="lib" path="lib/httpmime-4.5.2.jar"/>
 	<classpathentry kind="lib" path="lib/noggit-0.6.jar"/>
-	<classpathentry kind="lib" path="lib/solr-core-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/solr-solrj-5.5.1.jar"/>
+	<classpathentry kind="lib" path="lib/solr-core-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/solr-solrj-5.5.2.jar"/>
 	<classpathentry kind="lib" path="lib/stax2-api-3.1.4.jar"/>
 	<classpathentry kind="lib" path="lib/woodstox-core-asl-4.4.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-analyzers-common-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-analyzers-phonetic-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-classification-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-codecs-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-core-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-facet-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-grouping-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-highlighter-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-join-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-memory-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-misc-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-queries-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-queryparser-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-spatial-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-suggest-5.5.1.jar"/>
-	<classpathentry kind="lib" path="lib/lucene-backward-codecs-5.5.1.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-analyzers-common-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-analyzers-phonetic-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-classification-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-codecs-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-core-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-facet-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-grouping-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-highlighter-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-join-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-memory-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-misc-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-queries-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-queryparser-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-spatial-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-suggest-5.5.2.jar"/>
+	<classpathentry kind="lib" path="lib/lucene-backward-codecs-5.5.2.jar"/>
 	<classpathentry kind="con" path="org.eclipse.jdt.junit.JUNIT_CONTAINER/4"/>
 	<classpathentry kind="lib" path="lib/icu4j-57_1.jar"/>
 	<classpathentry kind="lib" path="lib/htmllexer.jar"/>
diff --git a/Dockerfile b/Dockerfile
deleted file mode 100644
index 14c159458..000000000
--- a/Dockerfile
+++ /dev/null
@@ -1,35 +0,0 @@
-# Base image : latest stable Debian 
-FROM debian:latest
-
-# Install needed packages
-RUN apt-get update && apt-get install -yq \
-	default-jdk \
-	ant \
-	git
-	
-# set current working dir
-WORKDIR /opt
-
-# clone main YaCy git repository (we need to clone git repository to generate correct version when building from source)
-RUN git clone https://github.com/yacy/yacy_search_server.git
-
-# trace content of source directory
-RUN ls -la /opt/yacy_search_server
-
-# set current working dir
-WORKDIR /opt/yacy_search_server
-	
-# Compile with ant
-RUN ant compile
-
-# make some cleaning to reduce image size
-RUN rm -rf .git && apt-get clean
-
-# Expose port 8090
-EXPOSE 8090
-
-# Set data volume : can be used to persist yacy data and configuration
-VOLUME ["/opt/yacy_search_server/DATA"]
-
-# Start yacy ind debug mode (-d) to display console logs and to wait for yacy process
-CMD sh /opt/yacy_search_server/startYACY.sh -d
diff --git a/build.xml b/build.xml
index 6d2e4388b..373c69dbc 100644
--- a/build.xml
+++ b/build.xml
@@ -208,22 +208,22 @@
     	<pathelement location="${lib}/json-simple-1.1.1.jar" />
     	<pathelement location="${lib}/jsoup-1.9.2.jar" />
     	<pathelement location="${lib}/log4j-over-slf4j-1.7.21.jar" />
-    	<pathelement location="${lib}/lucene-analyzers-common-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-analyzers-phonetic-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-backward-codecs-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-classification-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-codecs-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-core-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-facet-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-grouping-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-highlighter-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-join-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-memory-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-misc-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-queries-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-queryparser-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-spatial-5.5.1.jar" />
-    	<pathelement location="${lib}/lucene-suggest-5.5.1.jar" />
+    	<pathelement location="${lib}/lucene-analyzers-common-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-analyzers-phonetic-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-backward-codecs-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-classification-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-codecs-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-core-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-facet-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-grouping-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-highlighter-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-join-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-memory-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-misc-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-queries-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-queryparser-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-spatial-5.5.2.jar" />
+    	<pathelement location="${lib}/lucene-suggest-5.5.2.jar" />
 	<pathelement location="${lib}/jsonic-1.2.0.jar" />
 	<pathelement location="${lib}/langdetect.jar" />
     	<pathelement location="${lib}/metadata-extractor-2.9.1.jar" />
@@ -234,8 +234,8 @@
     	<pathelement location="${lib}/poi-scratchpad-3.14-20160307.jar" />
         <pathelement location="${lib}/slf4j-api-1.7.21.jar" />
         <pathelement location="${lib}/slf4j-jdk14-1.7.21.jar" />
-        <pathelement location="${lib}/solr-core-5.5.1.jar" />
-        <pathelement location="${lib}/solr-solrj-5.5.1.jar" />
+        <pathelement location="${lib}/solr-core-5.5.2.jar" />
+        <pathelement location="${lib}/solr-solrj-5.5.2.jar" />
     	<pathelement location="${lib}/spatial4j-0.5.jar" />
         <pathelement location="${lib}/stax2-api_3.1.4.jar" />        
     	<pathelement location="${lib}/webcat-swf-0.1.jar" />
diff --git a/lib/lucene-analyzers-common-5.5.1.jar b/lib/lucene-analyzers-common-5.5.2.jar
similarity index 65%
rename from lib/lucene-analyzers-common-5.5.1.jar
rename to lib/lucene-analyzers-common-5.5.2.jar
index ec29040ee..7506e1f98 100644
Binary files a/lib/lucene-analyzers-common-5.5.1.jar and b/lib/lucene-analyzers-common-5.5.2.jar differ
diff --git a/lib/lucene-analyzers-phonetic-5.5.1.jar b/lib/lucene-analyzers-phonetic-5.5.2.jar
similarity index 67%
rename from lib/lucene-analyzers-phonetic-5.5.1.jar
rename to lib/lucene-analyzers-phonetic-5.5.2.jar
index ccf216bd6..9b325a630 100644
Binary files a/lib/lucene-analyzers-phonetic-5.5.1.jar and b/lib/lucene-analyzers-phonetic-5.5.2.jar differ
diff --git a/lib/lucene-backward-codecs-5.5.1.jar b/lib/lucene-backward-codecs-5.5.2.jar
similarity index 69%
rename from lib/lucene-backward-codecs-5.5.1.jar
rename to lib/lucene-backward-codecs-5.5.2.jar
index b956d2eba..fbac8b98f 100644
Binary files a/lib/lucene-backward-codecs-5.5.1.jar and b/lib/lucene-backward-codecs-5.5.2.jar differ
diff --git a/lib/lucene-classification-5.5.1.jar b/lib/lucene-classification-5.5.2.jar
similarity index 91%
rename from lib/lucene-classification-5.5.1.jar
rename to lib/lucene-classification-5.5.2.jar
index 330769397..b5f0ad3ed 100644
Binary files a/lib/lucene-classification-5.5.1.jar and b/lib/lucene-classification-5.5.2.jar differ
diff --git a/lib/lucene-codecs-5.5.1.jar b/lib/lucene-codecs-5.5.2.jar
similarity index 80%
rename from lib/lucene-codecs-5.5.1.jar
rename to lib/lucene-codecs-5.5.2.jar
index fdc493651..5587a9835 100644
Binary files a/lib/lucene-codecs-5.5.1.jar and b/lib/lucene-codecs-5.5.2.jar differ
diff --git a/lib/lucene-core-5.5.1.jar b/lib/lucene-core-5.5.2.jar
similarity index 74%
rename from lib/lucene-core-5.5.1.jar
rename to lib/lucene-core-5.5.2.jar
index c52dd9e33..5015c5ff4 100644
Binary files a/lib/lucene-core-5.5.1.jar and b/lib/lucene-core-5.5.2.jar differ
diff --git a/lib/lucene-facet-5.5.1.jar b/lib/lucene-facet-5.5.2.jar
similarity index 82%
rename from lib/lucene-facet-5.5.1.jar
rename to lib/lucene-facet-5.5.2.jar
index 6079de49b..006d24a47 100644
Binary files a/lib/lucene-facet-5.5.1.jar and b/lib/lucene-facet-5.5.2.jar differ
diff --git a/lib/lucene-grouping-5.5.1.jar b/lib/lucene-grouping-5.5.2.jar
similarity index 80%
rename from lib/lucene-grouping-5.5.1.jar
rename to lib/lucene-grouping-5.5.2.jar
index ee839ac2d..37a938401 100644
Binary files a/lib/lucene-grouping-5.5.1.jar and b/lib/lucene-grouping-5.5.2.jar differ
diff --git a/lib/lucene-highlighter-5.5.1.jar b/lib/lucene-highlighter-5.5.2.jar
similarity index 71%
rename from lib/lucene-highlighter-5.5.1.jar
rename to lib/lucene-highlighter-5.5.2.jar
index 02cef29b0..6b5b7d818 100644
Binary files a/lib/lucene-highlighter-5.5.1.jar and b/lib/lucene-highlighter-5.5.2.jar differ
diff --git a/lib/lucene-join-5.5.1.jar b/lib/lucene-join-5.5.2.jar
similarity index 67%
rename from lib/lucene-join-5.5.1.jar
rename to lib/lucene-join-5.5.2.jar
index 250f4ef3e..1443093ca 100644
Binary files a/lib/lucene-join-5.5.1.jar and b/lib/lucene-join-5.5.2.jar differ
diff --git a/lib/lucene-memory-5.5.1.jar b/lib/lucene-memory-5.5.2.jar
similarity index 91%
rename from lib/lucene-memory-5.5.1.jar
rename to lib/lucene-memory-5.5.2.jar
index e35463843..539caf648 100644
Binary files a/lib/lucene-memory-5.5.1.jar and b/lib/lucene-memory-5.5.2.jar differ
diff --git a/lib/lucene-misc-5.5.1.jar b/lib/lucene-misc-5.5.2.jar
similarity index 80%
rename from lib/lucene-misc-5.5.1.jar
rename to lib/lucene-misc-5.5.2.jar
index ac0325d50..9fab30e40 100644
Binary files a/lib/lucene-misc-5.5.1.jar and b/lib/lucene-misc-5.5.2.jar differ
diff --git a/lib/lucene-queries-5.5.1.jar b/lib/lucene-queries-5.5.2.jar
similarity index 80%
rename from lib/lucene-queries-5.5.1.jar
rename to lib/lucene-queries-5.5.2.jar
index 543207653..284da010a 100644
Binary files a/lib/lucene-queries-5.5.1.jar and b/lib/lucene-queries-5.5.2.jar differ
diff --git a/lib/lucene-queryparser-5.5.1.jar b/lib/lucene-queryparser-5.5.2.jar
similarity index 67%
rename from lib/lucene-queryparser-5.5.1.jar
rename to lib/lucene-queryparser-5.5.2.jar
index 0d33f79fe..ed7c63be6 100644
Binary files a/lib/lucene-queryparser-5.5.1.jar and b/lib/lucene-queryparser-5.5.2.jar differ
diff --git a/lib/lucene-spatial-5.5.1.jar b/lib/lucene-spatial-5.5.2.jar
similarity index 78%
rename from lib/lucene-spatial-5.5.1.jar
rename to lib/lucene-spatial-5.5.2.jar
index 43ce7fab1..a8c9e4aef 100644
Binary files a/lib/lucene-spatial-5.5.1.jar and b/lib/lucene-spatial-5.5.2.jar differ
diff --git a/lib/lucene-suggest-5.5.1.jar b/lib/lucene-suggest-5.5.2.jar
similarity index 71%
rename from lib/lucene-suggest-5.5.1.jar
rename to lib/lucene-suggest-5.5.2.jar
index 898f3f5cb..1004d21b9 100644
Binary files a/lib/lucene-suggest-5.5.1.jar and b/lib/lucene-suggest-5.5.2.jar differ
diff --git a/lib/solr-core-5.5.1.jar b/lib/solr-core-5.5.2.jar
similarity index 68%
rename from lib/solr-core-5.5.1.jar
rename to lib/solr-core-5.5.2.jar
index 5f905be05..83f2bf412 100644
Binary files a/lib/solr-core-5.5.1.jar and b/lib/solr-core-5.5.2.jar differ
diff --git a/lib/solr-solrj-5.5.1.jar b/lib/solr-solrj-5.5.2.jar
similarity index 61%
rename from lib/solr-solrj-5.5.1.jar
rename to lib/solr-solrj-5.5.2.jar
index e9b49c09f..cc0a70e54 100644
Binary files a/lib/solr-solrj-5.5.1.jar and b/lib/solr-solrj-5.5.2.jar differ
diff --git a/pom.xml b/pom.xml
index 40e4e71e4..951ccb98b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -4,7 +4,7 @@
 
     <groupId>net.yacy</groupId>
     <artifactId>yacycore</artifactId>
-    <version>1.83</version>
+    <version>1.91</version>
     <packaging>jar</packaging>
     <description>YaCy - a Peer to Peer Web Search Engine</description>
     <name>YaCy Search Server</name>
@@ -34,7 +34,7 @@
         <maven.compiler.source>1.7</maven.compiler.source>
         <maven.compiler.target>1.7</maven.compiler.target>
         <!-- the Solr version used in dependency section for all related dependencies -->
-        <solr.version>5.5.1</solr.version> 
+        <solr.version>5.5.2</solr.version> 
         <!-- the Jetty version used in dependency section for all related dependencies -->
         <jetty.version>9.2.17.v20160517</jetty.version>