Error notification don't show up (widget)

Hi,

I have login form in widget by shortcode: [clean-login]

Everything’s fine, but when I type wrong password or login, there is no error message:
http://odyniec.ilawa.pl/

When I add shortcode on page, then it working both on page and on widget, sample: http://odyniec.ilawa.pl/login2/

But on another site it’s not working.

Can You help me? 🙂

https://ww.wp.xz.cn/plugins/clean-login/