fix attribute-Objectselection-Type

process/Attribute_lib/process.js

-import("system.logging");
 import("KeywordData_lib");
 import("Context_lib");
 import("system.util");
@@ -799,7 +798,7 @@ $AttributeTypes.OBJECTSELECTION = {
             project.getDataModels(project.DATAMODEL_KIND_ENTITY).forEach(
                 function (entity)
                 {
-                    if (entity[1] && this._selectableEntities[entity[0]])
+                    if (entity[1] && $AttributeTypes.OBJECTSELECTION._selectableEntities[entity[0]])
                         dropDownList.push([entity[0], translate.text(entity[1])]);
                 }
             );