diff --git a/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/ExtraFieldBuilder.java b/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/ExtraFieldBuilder.java
index 6ebcafe4a..a64fd8412 100644
--- a/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/ExtraFieldBuilder.java
+++ b/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/ExtraFieldBuilder.java
@@ -26,7 +26,7 @@ public class ExtraFieldBuilder extends FieldBuilder<ExtraField, ExtraFieldEntity
 	}
 
 	protected ExtraField buildChild(FieldSet fields, ExtraFieldEntity data, ExtraField model) {
-		if (fields.hasField(this.asIndexer(ExtraField._type))) model.setType(data.getType());
+		if (fields.hasField(this.asIndexer(ExtraField._dataType))) model.setDataType(data.getType());
 		return model;
 	}
 }
diff --git a/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/FieldBuilder.java b/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/FieldBuilder.java
index 5683d7da5..5314c2731 100644
--- a/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/FieldBuilder.java
+++ b/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/FieldBuilder.java
@@ -59,6 +59,7 @@ public abstract class FieldBuilder<Model extends Field, Entity extends FieldEnti
             if (fields.hasField(this.asIndexer(Model._placeholder))) m.setPlaceholder(d.getPlaceholder());
             if (fields.hasField(this.asIndexer(Model._ordinal))) m.setOrdinal(d.getOrdinal());
             if (fields.hasField(this.asIndexer(Model._required))) m.setRequired(d.isRequired());
+            this.buildChild(fields, d, m);
             models.add(m);
         }
         this.logger.debug("build {} items", Optional.of(models).map(List::size).orElse(0));
diff --git a/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/SystemFieldBuilder.java b/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/SystemFieldBuilder.java
index 3d023931c..3eefb6bde 100644
--- a/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/SystemFieldBuilder.java
+++ b/dmp-backend/core/src/main/java/eu/eudat/model/builder/dmpblueprintdefinition/SystemFieldBuilder.java
@@ -26,7 +26,7 @@ public class SystemFieldBuilder extends FieldBuilder<SystemField, SystemFieldEnt
 	}
 
 	protected SystemField buildChild(FieldSet fields, SystemFieldEntity data, SystemField model) {
-		if (fields.hasField(this.asIndexer(SystemField._type))) model.setType(data.getType());
+		if (fields.hasField(this.asIndexer(SystemField._systemFieldType))) model.setSystemFieldType(data.getType());
 		return model;
 	}
 }
diff --git a/dmp-backend/core/src/main/java/eu/eudat/model/dmpblueprintdefinition/ExtraField.java b/dmp-backend/core/src/main/java/eu/eudat/model/dmpblueprintdefinition/ExtraField.java
index b17162849..8bd1b4e52 100644
--- a/dmp-backend/core/src/main/java/eu/eudat/model/dmpblueprintdefinition/ExtraField.java
+++ b/dmp-backend/core/src/main/java/eu/eudat/model/dmpblueprintdefinition/ExtraField.java
@@ -4,14 +4,14 @@ import eu.eudat.commons.enums.DmpBlueprintExtraFieldDataType;
 
 public class ExtraField extends Field {
 
-	public final static String _type = "type";
-	private DmpBlueprintExtraFieldDataType type;
+	public final static String _dataType = "dataType";
+	private DmpBlueprintExtraFieldDataType dataType;
 
-	public DmpBlueprintExtraFieldDataType getType() {
-		return type;
+	public DmpBlueprintExtraFieldDataType getDataType() {
+		return dataType;
 	}
 
-	public void setType(DmpBlueprintExtraFieldDataType type) {
-		this.type = type;
+	public void setDataType(DmpBlueprintExtraFieldDataType dataType) {
+		this.dataType = dataType;
 	}
 }
diff --git a/dmp-backend/core/src/main/java/eu/eudat/model/dmpblueprintdefinition/SystemField.java b/dmp-backend/core/src/main/java/eu/eudat/model/dmpblueprintdefinition/SystemField.java
index 377c0db77..b75cdc33d 100644
--- a/dmp-backend/core/src/main/java/eu/eudat/model/dmpblueprintdefinition/SystemField.java
+++ b/dmp-backend/core/src/main/java/eu/eudat/model/dmpblueprintdefinition/SystemField.java
@@ -4,14 +4,14 @@ import eu.eudat.commons.enums.DmpBlueprintSystemFieldType;
 
 public class SystemField extends Field {
 
-	public final static String _type = "type";
-	private DmpBlueprintSystemFieldType type;
+	public final static String _systemFieldType = "systemFieldType";
+	private DmpBlueprintSystemFieldType systemFieldType;
 
-	public DmpBlueprintSystemFieldType getType() {
-		return type;
+	public DmpBlueprintSystemFieldType getSystemFieldType() {
+		return systemFieldType;
 	}
 
-	public void setType(DmpBlueprintSystemFieldType type) {
-		this.type = type;
+	public void setSystemFieldType(DmpBlueprintSystemFieldType systemFieldType) {
+		this.systemFieldType = systemFieldType;
 	}
 }
diff --git a/dmp-backend/core/src/main/java/eu/eudat/model/persist/dmpblueprintdefinition/FieldPersist.java b/dmp-backend/core/src/main/java/eu/eudat/model/persist/dmpblueprintdefinition/FieldPersist.java
index 95aaf8a31..69a36e177 100644
--- a/dmp-backend/core/src/main/java/eu/eudat/model/persist/dmpblueprintdefinition/FieldPersist.java
+++ b/dmp-backend/core/src/main/java/eu/eudat/model/persist/dmpblueprintdefinition/FieldPersist.java
@@ -16,8 +16,8 @@ import java.util.UUID;
 		include = JsonTypeInfo.As.PROPERTY,
 		property = "category")
 @JsonSubTypes({
-		@JsonSubTypes.Type(value = SystemFieldPersist.class, name = "System"),
-		@JsonSubTypes.Type(value = ExtraFieldPersist.class, name = "Extra")
+		@JsonSubTypes.Type(value = SystemFieldPersist.class, name = "0"),
+		@JsonSubTypes.Type(value = ExtraFieldPersist.class, name = "1")
 })
 public abstract class FieldPersist {
 	@NotNull(message = "{validation.empty}")
diff --git a/dmp-backend/web/src/main/resources/config/application.yml b/dmp-backend/web/src/main/resources/config/application.yml
index b621c8114..cd7cfe9ae 100644
--- a/dmp-backend/web/src/main/resources/config/application.yml
+++ b/dmp-backend/web/src/main/resources/config/application.yml
@@ -17,4 +17,5 @@ spring:
       optional:classpath:config/external.yml[.yml], optional:classpath:config/external-${spring.profiles.active}.yml[.yml], optional:file:../config/external-${spring.profiles.active}.yml[.yml],
       optional:classpath:config/cors.yml[.yml], optional:classpath:config/cors-${spring.profiles.active}.yml[.yml], optional:file:../config/cors-${spring.profiles.active}.yml[.yml],
       optional:classpath:config/swagger.yml[.yml], optional:classpath:config/swagger-${spring.profiles.active}.yml[.yml], optional:file:../config/swagger-${spring.profiles.active}.yml[.yml],
-      optional:classpath:config/deposit.yml[.yml], optional:classpath:config/deposit-${spring.profiles.active}.yml[.yml], optional:file:../config/deposit-${spring.profiles.active}.yml[.yml]
+      optional:classpath:config/deposit.yml[.yml], optional:classpath:config/deposit-${spring.profiles.active}.yml[.yml], optional:file:../config/deposit-${spring.profiles.active}.yml[.yml],
+      optional:classpath:config/errors.yml[.yml], optional:classpath:config/errors-${spring.profiles.active}.yml[.yml], optional:file:../config/errors-${spring.profiles.active}.yml[.yml]
diff --git a/dmp-backend/web/src/main/resources/config/errors.yml b/dmp-backend/web/src/main/resources/config/errors.yml
new file mode 100644
index 000000000..42c3b2392
--- /dev/null
+++ b/dmp-backend/web/src/main/resources/config/errors.yml
@@ -0,0 +1,28 @@
+error-thesaurus:
+  hash-conflict:
+    code: 100
+    message: there is a hash conflict for the item modifed. please reload to get the latest changes
+  forbidden:
+    code: 101
+    message: insufficient rights
+  system-error:
+    code: 102
+    message: an unexpected system error occured
+  missing-tenant:
+    code: 103
+    message: tenant scope not provided
+  model-validation:
+    code: 106
+    message: validation error
+  tenant-code-required:
+    code: 108
+    message: tenant code required
+  tenant-name-required:
+    code: 109
+    message: tenant name required
+  index-already-exists:
+    code: 110
+    message: index already exists
+  tenant-not-allowed:
+    code: 113
+    message: tenant not allowed