diff --git a/.gitignore b/.gitignore
index 9d3a0c2ad77367410b9accee631cae1ef3d5f676..80fc95afc0f952466350fcfa145bef195a991e67 100644
--- a/.gitignore
+++ b/.gitignore
@@ -103,11 +103,8 @@ ENV/
 
 .DS_Store
 
-# frontend
-node_modules
-/.vscode
-package-lock.json
-
 # PyCharm IDE
 .idea/
 
+/.vscode
+.tool-versions
diff --git a/frontend/.nvmrc b/frontend/.nvmrc
deleted file mode 100644
index 66df3b7ab2d11466aa49935b4011e1fe37364f4b..0000000000000000000000000000000000000000
--- a/frontend/.nvmrc
+++ /dev/null
@@ -1 +0,0 @@
-12.16.1
diff --git a/frontend/components/ScalarsPage/ScalarChart.tsx b/frontend/components/ScalarsPage/ScalarChart.tsx
index 628375f03f9d359ec61f2da8c1e7d0ebd1b12b9d..7d4a341957aa04e0eb90422887947d25c79c6a5a 100644
--- a/frontend/components/ScalarsPage/ScalarChart.tsx
+++ b/frontend/components/ScalarsPage/ScalarChart.tsx
@@ -72,7 +72,7 @@ const ScalarChart: FunctionComponent<ScalarChartProps> = ({
 }) => {
     const {t, i18n} = useTranslation(['scalars', 'common']);
 
-    const {data: datasets, error, loading} = useRunningRequest<Dataset[]>(
+    const {data: datasets, error, loading} = useRunningRequest<(Dataset | null)[]>(
         runs.map(run => `/scalars/list?${queryString.stringify({run, tag})}`),
         !!running,
         (...urls) => cycleFetcher(urls)
@@ -84,7 +84,7 @@ const ScalarChart: FunctionComponent<ScalarChartProps> = ({
 
     const transformParams = useMemo(
         () => ({
-            datasets: datasets ?? [],
+            datasets: datasets?.map(data => data ?? []) ?? [],
             smoothing
         }),
         [datasets, smoothing]
diff --git a/frontend/package.json b/frontend/package.json
index ef36564d6763cc00dc6a01d7648b157898767d8a..d13f0a057857744ad5f8979400d425d50d5346bc 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -1,6 +1,6 @@
 {
     "name": "visualdl",
-    "version": "2.0.0-beta.22",
+    "version": "2.0.0-beta.23",
     "title": "VisualDL",
     "description": "A platform to visualize the deep learning process and result.",
     "keywords": [
diff --git a/frontend/utils/mock.ts b/frontend/utils/mock.ts
index 1d4484519e0610fb4f28c1aba7d8524e2253986c..256df05497ebd5acb5b849a4599297a70f0031e1 100644
--- a/frontend/utils/mock.ts
+++ b/frontend/utils/mock.ts
@@ -42,7 +42,7 @@ export default (options: Options) => {
                 res.send(Buffer.from(mock));
             } else {
                 const result = JSON.parse(faker.fake(JSON.stringify(mock, null, 4)));
-                if ('status' in result && 'data' in result) {
+                if (result && 'status' in result && 'data' in result) {
                     res.json(result);
                 } else {
                     res.json({status: 0, msg: '', data: result});
@@ -50,6 +50,8 @@ export default (options: Options) => {
             }
         } catch (e) {
             res.status(500).send(e.message);
+            // eslint-disable-next-line no-console
+            console.error(e);
         }
     };
 };