How to fix: Cannot read properties of undefined (reading 'type')

Dash Python
21

app.py

app = dash.Dash(
    __name__,
    external_stylesheets=[dbc.themes.MATERIA, dbc.icons.BOOTSTRAP, dbc.icons.FONT_AWESOME],
    suppress_callback_exceptions=True,
    use_pages=True,
    background_callback_manager=background_callback_manager
)

navbar = dbc.NavbarSimple(
    children=[
            dbc.NavItem(dbc.NavLink(page['name'], href=page["path"]))
            for page in dash.page_registry.values()
    ])

app.layout = dbc.Container(
    id="root",
    fluid=True,
    className="container-fluid",
    children=[
        dcc.Location(id="url", refresh=False),
        dcc.Store(id='changed_url', storage_type='session'),
        navbar,
        dbc.Row([html.P()]), 
        dash.page_container
    ]
)

there shouldn’t be anything else here, should there? besides imports?

22

It’s really hard to help you if you drop code snippets here.

Here a working multipage app:

Another: