Laravel 5.6 error messages display issue

I have an issue with laravel 5.6, for which error messages are showing at login page. However, after login, all error messages are working well.

When I check in console it shows following error:

[Vue warn]: Unknown custom element: <flash> - did you register the component 
correctly? For recursive components, make sure to provide the "name" option.

(found in <Root>)

Can anyone help?

Thanks in advance.

via Chebli Mohamed