diff --git a/packages/base/src/commands.ts b/packages/base/src/commands.ts
index 87b38d31..f76e4577 100644
--- a/packages/base/src/commands.ts
+++ b/packages/base/src/commands.ts
@@ -285,12 +285,6 @@ namespace Private {
       current.context.model
         .readGeoJSON(filepath)
         .then(async geoJSONData => {
-          if (geoJSONData === undefined) {
-            showErrorMessage(
-              'Error reading GeoJSON',
-              'An error occurred while reading the GeoJSON file'
-            );
-          }
           const name = PathExt.basename(filepath, '.json');
           const valid = validate(geoJSONData);
           if (!valid) {
@@ -345,13 +339,15 @@ namespace Private {
         default: (model: IJupyterGISModel) => {
           return {
             name: 'VectorSource',
-            source: sources[Object.keys(sources)[0]] ?? null
+            source: Object.keys(sources)[0] ?? null
           };
         }
       };
 
       current.context.model.syncFormData(form);
 
+      FORM_SCHEMA['VectorLayer'].properties.source.enumNames = Object.values(sources);
+      FORM_SCHEMA['VectorLayer'].properties.source.enum = Object.keys(sources);
       const dialog = new FormDialog({
         context: current.context,
         title: form.title,
@@ -365,14 +361,10 @@ namespace Private {
 
           const { name, ...parameters } = props;
 
-          const source = Object.keys(sources).find(
-            key => sources[key] === parameters.source
-          );
-
           const layerModel: IJGISLayer = {
             type: 'VectorLayer',
             parameters: {
-              source,
+              source: parameters.source,
               type: parameters.type,
               color: parameters.color,
               opacity: parameters.opacity
diff --git a/packages/base/src/formdialog.tsx b/packages/base/src/formdialog.tsx
index dd057552..9755a946 100644
--- a/packages/base/src/formdialog.tsx
+++ b/packages/base/src/formdialog.tsx
@@ -28,6 +28,7 @@ export class FormDialog extends Dialog<IDict> {
         this.resolve(0);
       };
     }
+
     const filePath = options.context.path;
     const jGISModel = options.context.model;
     const body = (
diff --git a/packages/base/style/dialog.css b/packages/base/style/dialog.css
index aa4aea06..13e375b7 100644
--- a/packages/base/style/dialog.css
+++ b/packages/base/style/dialog.css
@@ -3,6 +3,10 @@
 | Distributed under the terms of the Modified BSD License.
 |---------------------------------------------------------------------------- */
 
+.jp-SchemaForm .jp-select-wrapper select {
+  background-image: unset;
+}
+
 .jp-gis-addDataSourceBody > :not(:first-child) {
   margin-top: 1em;
 }
diff --git a/packages/schema/src/model.ts b/packages/schema/src/model.ts
index 361d324f..282583a1 100644
--- a/packages/schema/src/model.ts
+++ b/packages/schema/src/model.ts
@@ -1,6 +1,5 @@
 import { ICollaborativeDrive } from '@jupyter/docprovider';
 import { MapChange } from '@jupyter/ydoc';
-import { showErrorMessage } from '@jupyterlab/apputils';
 import { IChangedArgs } from '@jupyterlab/coreutils';
 import { DocumentRegistry } from '@jupyterlab/docregistry';
 import { PartialJSONObject } from '@lumino/coreutils';
@@ -253,8 +252,7 @@ export class JupyterGISModel implements IJupyterGISModel {
         return JSON.parse(contentModel.content);
       })
       .catch(e => {
-        showErrorMessage('Error opening GeoJSON file', e);
-        return;
+        throw(e);
       });
   }