Error 404

Hello.
I have some problem with page of category. And your website have the same problem.
https://demo.anspress.io/askbug/questions/categories/
And I also lost the categories in the control panel.
Can you fix it?
And I also tried switching here on your website. And I got a multiple nesting frame.
https://anspress.io/demo/?product=anspress
http://joxi.ru/Dr837Nju4Z5dXA