Categories do not contain any posts - Category Widget For WordPress

Hi

I’m making a non-profit project for a Judo club based on Sparkling theme (maxart.com.pl/ippon), but I got something really wrong as the posts which I add to any of the categories do not show up when I click on the category in the menu. It says ”Oops! The page could not be found”. I switched off all the plugins but it didn’t help. Do you have any idea what could be causing this issue? Thanks in advance.

BTW :slight_smile:
I didn’t get any of the Sparkling plugins. Is there any place where you could download them? I guess both these columns are achieved by using the plugins:

I see that you are already using Sparkling Popular Posts Widget. Another widget is called Sparkling Categories that you can enable via WordPress Dashboard >> Appearance >> Widgets.

Let me know if you need any further assistance with these widgets.