FELIX-6554 : Exception while starting Felix Configurator
diff --git a/configurator/src/main/java/org/apache/felix/configurator/impl/Configurator.java b/configurator/src/main/java/org/apache/felix/configurator/impl/Configurator.java
index b7bab7c..929e331 100644
--- a/configurator/src/main/java/org/apache/felix/configurator/impl/Configurator.java
+++ b/configurator/src/main/java/org/apache/felix/configurator/impl/Configurator.java
@@ -288,7 +288,7 @@
                 processAddBundle(b);
             }
         }
-        for(final long id : state.getKnownBundleIds()) {
+        for(final long id : new HashSet<>(state.getKnownBundleIds())) {
             if ( !ids.contains(id) ) {
                 processRemoveBundle(id);
             }