diff --git a/htroot/yacy/hello.java b/htroot/yacy/hello.java
index 66733a88e..54ca87d8e 100644
--- a/htroot/yacy/hello.java
+++ b/htroot/yacy/hello.java
@@ -47,6 +47,7 @@
 // if the shell's current path is HTROOT
 
 import java.net.InetAddress;
+import java.util.ConcurrentModificationException;
 import java.util.Iterator;
 import java.util.Map;
 
@@ -210,10 +211,12 @@ public final class hello {
                 Iterator<yacySeed> si = ySeeds.values().iterator();
                 yacySeed s;
                 while (si.hasNext()) {
-                	s = (yacySeed) si.next();
-                    if ((s != null) && (s.isProper() == null)) {
+                	s = si.next();
+                    if ((s != null) && (s.isProper() == null)) try {
                         seeds.append("seed").append(count).append('=').append(s.genSeedStr(key)).append(serverCore.CRLF_STRING);
                         count++;
+                    } catch (ConcurrentModificationException e) {
+                        e.printStackTrace();
                     }
                 }
             }
diff --git a/source/de/anomic/server/serverCodings.java b/source/de/anomic/server/serverCodings.java
index 28bb54900..a6320b045 100644
--- a/source/de/anomic/server/serverCodings.java
+++ b/source/de/anomic/server/serverCodings.java
@@ -195,18 +195,19 @@ public final class serverCodings {
     }
 
     public static String map2string(Map<String, String> m, String separator, boolean braces) {
-        final StringBuffer buf = new StringBuffer(20 * m.size());
-        if (braces) { buf.append("{"); }
-        final Iterator<Map.Entry<String, String>> i = m.entrySet().iterator();
-        while (i.hasNext()) {
-            final Entry<String, String> e = i.next();
-            buf.append(e.getKey()).append('=');
-            if (e.getValue() != null) { buf.append(e.getValue()); }
-            buf.append(separator);
+        // m must be synchronized to prevent that a ConcurrentModificationException occurs
+        synchronized (m) {
+            final StringBuffer buf = new StringBuffer(20 * m.size());
+            if (braces) { buf.append("{"); }
+            for (Entry<String, String> e: m.entrySet()) {
+                buf.append(e.getKey()).append('=');
+                if (e.getValue() != null) { buf.append(e.getValue()); }
+                buf.append(separator);
+            }
+            if (buf.length() > 1) { buf.setLength(buf.length() - 1); } // remove last separator
+            if (braces) { buf.append("}"); }
+            return new String(buf);
         }
-        if (buf.length() > 1) { buf.setLength(buf.length() - 1); } // remove last separator
-        if (braces) { buf.append("}"); }
-        return new String(buf);
     }
 
     public static Set<String> string2set(String string, String separator) {