2 files changed, 7 insertions, 2 deletions
diff --git a/src/client/northstar/dash-fields/HistogramField.ts b/src/client/northstar/dash-fields/HistogramField.ts
index 1ee2189b9..31040a474 100644
--- a/src/client/northstar/dash-fields/HistogramField.ts
+++ b/src/client/northstar/dash-fields/HistogramField.ts
@@ -3,10 +3,11 @@ import { custom, serializable } from "serializr";
 import { ColumnAttributeModel } from "../../../client/northstar/core/attribute/AttributeModel";
 import { AttributeTransformationModel } from "../../../client/northstar/core/attribute/AttributeTransformationModel";
 import { HistogramOperation } from "../../../client/northstar/operations/HistogramOperation";
-import { ObjectField, Copy } from "../../../new_fields/ObjectField";
+import { ObjectField } from "../../../new_fields/ObjectField";
 import { CurrentUserUtils } from "../../../server/authentication/models/current_user_utils";
 import { OmitKeys } from "../../../Utils";
 import { Deserializable } from "../../util/SerializationHelper";
+import { Copy, ToScriptString } from "../../../new_fields/FieldSymbols";
 
 function serialize(field: HistogramField) {
     let obj = OmitKeys(field, ['Links', 'BrushLinks', 'Result', 'BrushColors', 'FilterModels', 'FilterOperand']).omit;
@@ -55,4 +56,8 @@ export class HistogramField extends ObjectField {
         let z = this.HistoOp.Copy;
         return new HistogramField(HistogramOperation.Duplicate(this.HistoOp));
     }
+
+    [ToScriptString]() {
+        return "invalid";
+    }
 }
 \ No newline at end of file
diff --git a/src/client/northstar/dash-nodes/HistogramBox.tsx b/src/client/northstar/dash-nodes/HistogramBox.tsx
index eb1ad69b7..a9646ed31 100644
--- a/src/client/northstar/dash-nodes/HistogramBox.tsx
+++ b/src/client/northstar/dash-nodes/HistogramBox.tsx
@@ -19,7 +19,7 @@ import { HistogramLabelPrimitives } from "./HistogramLabelPrimitives";
 import { StyleConstants } from "../utils/StyleContants";
 import { Cast } from "../../../new_fields/Types";
 import { Doc, DocListCast, DocListCastAsync } from "../../../new_fields/Doc";
-import { Id } from "../../../new_fields/RefField";
+import { Id } from "../../../new_fields/FieldSymbols";
 
 
 @observer