diff --git a/gcm4/src/main/java/plugins/groups/GroupsPluginData.java b/gcm4/src/main/java/plugins/groups/GroupsPluginData.java
index f0dd469ca..b59679a1a 100644
--- a/gcm4/src/main/java/plugins/groups/GroupsPluginData.java
+++ b/gcm4/src/main/java/plugins/groups/GroupsPluginData.java
@@ -254,11 +254,15 @@ private Builder(Data data) {
 		 * 
 		 */
 		public GroupsPluginData build() {
+			try {
 			if (!data.locked) {
 				validateData();
 			}
 			ensureImmutability();
 			return new GroupsPluginData(data);
+			}finally {
+				data = new Data();
+			}
 		}
 
 		/**
diff --git a/gcm4/src/main/java/plugins/materials/MaterialsPluginData.java b/gcm4/src/main/java/plugins/materials/MaterialsPluginData.java
index 69fef0113..81a010443 100644
--- a/gcm4/src/main/java/plugins/materials/MaterialsPluginData.java
+++ b/gcm4/src/main/java/plugins/materials/MaterialsPluginData.java
@@ -247,11 +247,15 @@ public Builder addStage(final StageId stageId, final boolean offered, final Mate
 		 */
 
 		public MaterialsPluginData build() {
+			try {
 			if (!data.locked) {
 				validateData();
 			}
 			ensureImmutability();
 			return new MaterialsPluginData(data);
+			}finally {
+				data = new Data();
+			}
 
 		}
 
diff --git a/gcm4/src/main/java/plugins/partitions/testsupport/attributes/AttributesPluginData.java b/gcm4/src/main/java/plugins/partitions/testsupport/attributes/AttributesPluginData.java
index b5537cde6..922fea89b 100644
--- a/gcm4/src/main/java/plugins/partitions/testsupport/attributes/AttributesPluginData.java
+++ b/gcm4/src/main/java/plugins/partitions/testsupport/attributes/AttributesPluginData.java
@@ -56,8 +56,12 @@ private void ensureImmutability() {
 		 * Returns the {@linkplain AttributesPluginData} from the collected data
 		 */
 		public AttributesPluginData build() {
-			ensureImmutability();
-			return new AttributesPluginData(data);
+			try {
+				ensureImmutability();
+				return new AttributesPluginData(data);
+			} finally {
+				data = new Data();
+			}
 		}
 
 		/**
diff --git a/gcm4/src/main/java/plugins/people/PeoplePluginData.java b/gcm4/src/main/java/plugins/people/PeoplePluginData.java
index a3e186f4f..dd942cc98 100644
--- a/gcm4/src/main/java/plugins/people/PeoplePluginData.java
+++ b/gcm4/src/main/java/plugins/people/PeoplePluginData.java
@@ -155,7 +155,7 @@ private void ensureImmutability() {
 						a = low;
 						b = high;
 					} else {
-						if (low > b+1) {
+						if (low > b + 1) {
 							count += (b - a + 1);
 							list2.add(new PersonRange(a, b));
 							a = low;
@@ -179,11 +179,11 @@ private void ensureImmutability() {
 
 				data.personRanges = list2;
 				data.personIds = new ArrayList<>(count);
-				
-				if(data.personCount<0) {
+
+				if (data.personCount < 0) {
 					data.personCount = 0;
-					if(!data.personRanges.isEmpty()) {
-						data.personCount = data.personRanges.get(data.personRanges.size()-1).getHighPersonId()+1;
+					if (!data.personRanges.isEmpty()) {
+						data.personCount = data.personRanges.get(data.personRanges.size() - 1).getHighPersonId() + 1;
 					}
 				}
 
@@ -215,9 +215,13 @@ private Builder(Data data) {
 		 * 
 		 */
 		public PeoplePluginData build() {
-			validate();
-			ensureImmutability();
-			return new PeoplePluginData(data);
+			try {
+				validate();
+				ensureImmutability();
+				return new PeoplePluginData(data);
+			} finally {
+				data = new Data();
+			}
 		}
 
 		/**
diff --git a/gcm4/src/main/java/plugins/personproperties/PersonPropertiesPluginData.java b/gcm4/src/main/java/plugins/personproperties/PersonPropertiesPluginData.java
index bc307536f..1e1af1f78 100644
--- a/gcm4/src/main/java/plugins/personproperties/PersonPropertiesPluginData.java
+++ b/gcm4/src/main/java/plugins/personproperties/PersonPropertiesPluginData.java
@@ -135,11 +135,15 @@ private Builder(Data data) {
 		 * 
 		 */
 		public PersonPropertiesPluginData build() {
+			try {
 			if (!data.locked) {
 				validateData();
 			}
 			ensureImmutability();
 			return new PersonPropertiesPluginData(data);
+			}finally {
+				data = new Data();
+			}
 		}
 
 		/**
diff --git a/gcm4/src/main/java/plugins/regions/RegionsPluginData.java b/gcm4/src/main/java/plugins/regions/RegionsPluginData.java
index 0fe3b27da..550281fdb 100644
--- a/gcm4/src/main/java/plugins/regions/RegionsPluginData.java
+++ b/gcm4/src/main/java/plugins/regions/RegionsPluginData.java
@@ -67,10 +67,14 @@ public Data(Data data) {
 
 		@Override
 		public boolean equals(Object o) {
-			if (this == o) return true;
-			if (!(o instanceof Data)) return false;
+			if (this == o)
+				return true;
+			if (!(o instanceof Data))
+				return false;
 			Data data = (Data) o;
-			return locked == data.locked && regionPropertyDefinitions.equals(data.regionPropertyDefinitions) && regionIds.equals(data.regionIds) && regionArrivalTimeTrackingPolicy == data.regionArrivalTimeTrackingPolicy && regionPropertyValues.equals(data.regionPropertyValues) && emptyRegionPropertyMap.equals(data.emptyRegionPropertyMap) && personRegions.equals(data.personRegions);
+			return locked == data.locked && regionPropertyDefinitions.equals(data.regionPropertyDefinitions) && regionIds.equals(data.regionIds)
+					&& regionArrivalTimeTrackingPolicy == data.regionArrivalTimeTrackingPolicy && regionPropertyValues.equals(data.regionPropertyValues)
+					&& emptyRegionPropertyMap.equals(data.emptyRegionPropertyMap) && personRegions.equals(data.personRegions);
 		}
 
 		@Override
@@ -171,11 +175,15 @@ private Builder(Data data) {
 		 * 
 		 */
 		public RegionsPluginData build() {
-			if (!data.locked) {				
-				validateData();
+			try {
+				if (!data.locked) {
+					validateData();
+				}
+				ensureImmutability();
+				return new RegionsPluginData(data);
+			} finally {
+				data = new Data();
 			}
-			ensureImmutability();
-			return new RegionsPluginData(data);
 
 		}
 
@@ -454,8 +462,10 @@ public PluginDataBuilder getEmptyBuilder() {
 
 	@Override
 	public boolean equals(Object o) {
-		if (this == o) return true;
-		if (!(o instanceof RegionsPluginData)) return false;
+		if (this == o)
+			return true;
+		if (!(o instanceof RegionsPluginData))
+			return false;
 		RegionsPluginData that = (RegionsPluginData) o;
 		return data.equals(that.data);
 	}
diff --git a/gcm4/src/main/java/plugins/resources/ResourcesPluginData.java b/gcm4/src/main/java/plugins/resources/ResourcesPluginData.java
index 6c75cba67..5fb16b5a4 100644
--- a/gcm4/src/main/java/plugins/resources/ResourcesPluginData.java
+++ b/gcm4/src/main/java/plugins/resources/ResourcesPluginData.java
@@ -252,11 +252,15 @@ private Builder(Data data) {
 		 * 
 		 */
 		public ResourcesPluginData build() {
-			if (!data.locked) {
-				validateData();
+			try {
+				if (!data.locked) {
+					validateData();
+				}
+				ensureImmutability();
+				return new ResourcesPluginData(data);
+			} finally {
+				data = new Data();
 			}
-			ensureImmutability();
-			return new ResourcesPluginData(data);
 		}
 
 		/**
diff --git a/gcm4/src/main/java/plugins/stochastics/StochasticsPluginData.java b/gcm4/src/main/java/plugins/stochastics/StochasticsPluginData.java
index e1f732594..d955bb64b 100644
--- a/gcm4/src/main/java/plugins/stochastics/StochasticsPluginData.java
+++ b/gcm4/src/main/java/plugins/stochastics/StochasticsPluginData.java
@@ -152,11 +152,15 @@ private void validateData() {
 		 * 
 		 */
 		public StochasticsPluginData build() {
+			try {
 			if (!data.locked) {
 				validateData();
 			}
 			ensureImmutability();
 			return new StochasticsPluginData(data);
+			}finally {
+				data = new Data();
+			}
 		}
 
 		/**