diff --git a/package.json b/package.json
index 3475622c3e..f41db00c27 100644
--- a/package.json
+++ b/package.json
@@ -3,8 +3,8 @@
     "version": "0.0.1",
     "private": true,
     "devDependencies": {
-        "cross-env": "^7.0.3",
         "@tailwindcss/ui": "^0.1.3",
+        "cross-env": "^7.0.3",
         "cssnano": "^4.1.10",
         "del": "^6.0.0",
         "gulp": "^4.0.2",
diff --git a/src/main/frontend/components/header.cljs b/src/main/frontend/components/header.cljs
index 761b1dccb5..b84640201a 100644
--- a/src/main/frontend/components/header.cljs
+++ b/src/main/frontend/components/header.cljs
@@ -144,15 +144,17 @@
         (repo/repos-dropdown true)]
 
        (when (and (nfs/supported?) (empty? repos))
-         [:a.text-sm.font-medium.opacity-70.hover:opacity-100.ml-3
-          {:on-click (fn []
-                       (nfs/ls-dir-files))
-           :title (t :open-a-directory)}
-          [:div.flex.flex-row.text-center
-           [:span.inline-block svg/folder-add]
-           (when-not config/mobile?
-             [:span.ml-1 {:style {:margin-top 2}}
-              (t :open)])]])
+         (ui/tooltip
+          "Warning: this is an experimental feature, please only use it for testing purpose."
+          [:a.text-sm.font-medium.opacity-70.hover:opacity-100.ml-3.block
+           {:on-click (fn []
+                        (nfs/ls-dir-files))}
+           [:div.flex.flex-row.text-center
+            [:span.inline-block svg/folder-add]
+            (when-not config/mobile?
+              [:span.ml-1 {:style {:margin-top 2}}
+               (t :open)])]]
+          {:label-style {:width 200}}))
 
        (if config/publishing?
          [:a.text-sm.font-medium.ml-3 {:href (rfe/href :graph)}
diff --git a/src/main/frontend/components/repo.cljs b/src/main/frontend/components/repo.cljs
index 9c1f995e59..93322c4295 100644
--- a/src/main/frontend/components/repo.cljs
+++ b/src/main/frontend/components/repo.cljs
@@ -40,9 +40,11 @@
                "Add another git repo"
                :href (rfe/href :repo-add))])
            (when (nfs-handler/supported?)
-             (ui/button
-              (t :open-a-directory)
-              :on-click nfs-handler/ls-dir-files))]
+             [:div.flex.flex-col
+              [:div (ui/button
+                      (t :open-a-directory)
+                      :on-click nfs-handler/ls-dir-files)]
+              [:span.warning.mt-2.text-sm "Warning: this is an experimental feature, please only use it for testing purpose."]])]
           (for [{:keys [id url] :as repo} repos]
             (let [local? (config/local-db? url)]
               [:div.flex.justify-between.mb-1 {:key id}
diff --git a/src/main/frontend/handler/web/nfs.cljs b/src/main/frontend/handler/web/nfs.cljs
index f1eca431ec..61097d04c9 100644
--- a/src/main/frontend/handler/web/nfs.cljs
+++ b/src/main/frontend/handler/web/nfs.cljs
@@ -105,7 +105,8 @@
            (p/catch (fn [error]
                       (log/error :nfs/load-files-error error)))))
      (p/catch (fn [error]
-                (log/error :nfs/open-dir-error error))))))
+                (when (not= "AbortError" (gobj/get error "name"))
+                  (log/error :nfs/open-dir-error error)))))))
 
 (defn open-file-picker
   "Shows a file picker that lets a user select a single existing file, returning a handle for the selected file. "
diff --git a/src/main/frontend/ui.cljs b/src/main/frontend/ui.cljs
index 51c850eae4..a6e71bca0b 100644
--- a/src/main/frontend/ui.cljs
+++ b/src/main/frontend/ui.cljs
@@ -384,11 +384,16 @@
       :aria-hidden "true"}]]])
 
 (defn tooltip
-  [label children]
-  [:div.Tooltip {:style {:display "inline"}}
-   [:div {:class "Tooltip__label"}
-    label]
-   children])
+  ([label children]
+   (tooltip label children {}))
+  ([label children {:keys [label-style]}]
+   [:div.Tooltip {:style {:display "inline"}}
+    [:div (cond->
+            {:class "Tooltip__label"}
+            label-style
+            (assoc :style label-style))
+     label]
+    children]))
 
 (defonce modal-show? (atom false))
 (rum/defc modal-overlay