Dash graph generates "react@16.v1_2_2m1581098003.8.6.js:2726 Warning: Failed prop type: The prop `isRequired` is marked as required in `<<anonymous>>`, but its value is `undefined`."

Here is my very simple code:

import plotly.graph_objs as go
import dash
import dash_core_components as dcc
import dash_html_components as html

app = dash.Dash(name)

app.layout = html.Div([
html.Div([
dcc.Graph(id=‘graph-24H’, figure=go.Figure()),
], className=“row”),
])

if name == “main”:
import socket
app.run_server(host = socket.gethostbyname(socket.gethostname()), port = 8002, debug = True)

However, if I run the code on Chrome, and go to Inspect, Console, I got:
react@16.v1_2_2m1581098003.8.6.js:2726 Warning: Failed prop type: The prop isRequired is marked as required in <<anonymous>>, but its value is undefined.
in Unknown (created by n)
in n (created by CheckedComponent)
in CheckedComponent (created by TreeContainer)
in UnconnectedComponentErrorBoundary (created by Connect(UnconnectedComponentErrorBoundary))
in Connect(UnconnectedComponentErrorBoundary) (created by TreeContainer)
in TreeContainer (created by Connect(TreeContainer))
in Connect(TreeContainer) (created by TreeContainer)
in div (created by u)
in u (created by CheckedComponent)
in CheckedComponent (created by TreeContainer)
in UnconnectedComponentErrorBoundary (created by Connect(UnconnectedComponentErrorBoundary))
in Connect(UnconnectedComponentErrorBoundary) (created by TreeContainer)
in TreeContainer (created by Connect(TreeContainer))
in Connect(TreeContainer) (created by TreeContainer)
in div (created by u)
in u (created by CheckedComponent)
in CheckedComponent (created by TreeContainer)
in UnconnectedComponentErrorBoundary (created by Connect(UnconnectedComponentErrorBoundary))
in Connect(UnconnectedComponentErrorBoundary) (created by TreeContainer)
in TreeContainer (created by Connect(TreeContainer))
in Connect(TreeContainer) (created by UnconnectedContainer)
in div (created by UnconnectedGlobalErrorContainer)
in div (created by GlobalErrorOverlay)
in div (created by GlobalErrorOverlay)
in GlobalErrorOverlay (created by DebugMenu)
in div (created by DebugMenu)
in DebugMenu (created by UnconnectedGlobalErrorContainer)
in div (created by UnconnectedGlobalErrorContainer)
in UnconnectedGlobalErrorContainer (created by Connect(UnconnectedGlobalErrorContainer))
in Connect(UnconnectedGlobalErrorContainer) (created by UnconnectedContainer)
in UnconnectedContainer (created by Connect(UnconnectedContainer))
in Connect(UnconnectedContainer) (created by UnconnectedAppContainer)
in UnconnectedAppContainer (created by Connect(UnconnectedAppContainer))
in Connect(UnconnectedAppContainer) (created by AppProvider)
in Provider (created by AppProvider)
in AppProvider

Anyone had similar problems?