diff --git a/main.py b/main.py
index f99f00e..bb73de7 100644
--- a/main.py
+++ b/main.py
@@ -224,6 +224,9 @@ def index():
                             'text-caption q-pa-md')
 
     def _render_pane_file_selector(pane_state: AppState):
+        if not pane_state.current_dir.exists():
+            ui.label('Directory not found.').classes('text-warning')
+            return
         json_files = sorted(pane_state.current_dir.glob('*.json'))
         json_files = [f for f in json_files if f.name not in (
             '.editor_config.json', '.editor_snippets.json')]
@@ -422,6 +425,9 @@ def render_sidebar(state: AppState, dual_pane: dict):
     with ui.card().classes('w-full q-pa-md q-mb-md'):
         @ui.refreshable
         def render_file_list():
+            if not state.current_dir.exists():
+                ui.label('Directory not found.').classes('text-warning')
+                return
             json_files = sorted(state.current_dir.glob('*.json'))
             json_files = [f for f in json_files if f.name not in ('.editor_config.json', '.editor_snippets.json')]
 
diff --git a/tab_timeline_ng.py b/tab_timeline_ng.py
index 7f49b09..6c0c004 100644
--- a/tab_timeline_ng.py
+++ b/tab_timeline_ng.py
@@ -130,10 +130,11 @@ def _render_batch_delete(htree, data, file_path, state, refresh_fn):
     ).classes('text-warning q-mt-md')
 
     def do_batch_delete():
-        _delete_nodes(htree, data, file_path, valid)
+        current_valid = state.timeline_selected_nodes & set(htree.nodes.keys())
+        _delete_nodes(htree, data, file_path, current_valid)
         state.timeline_selected_nodes = set()
         ui.notify(
-            f'Deleted {count} node{"s" if count != 1 else ""}!',
+            f'Deleted {len(current_valid)} node{"s" if len(current_valid) != 1 else ""}!',
             type='positive')
         refresh_fn()
 
@@ -288,7 +289,7 @@ def _render_graphviz(dot_source: str):
 
 def _restore_node(data, node, htree, file_path, state: AppState):
     """Restore a history node as the current version."""
-    node_data = node['data']
+    node_data = copy.deepcopy(node['data'])
     if KEY_BATCH_DATA not in node_data and KEY_BATCH_DATA in data:
         del data[KEY_BATCH_DATA]
     data.update(node_data)