Unwanted widget appeared in mainbody bottom area

As the title says, I have unwanted widgets appearing in mainbody bottom widget area.
The page in question is: http://www.arika.co/questions/

Please advise on how to fix this. Thank you in advance!

Hello,

Did you install WooCommerce or other Ecommerce plugin?

No, I installed this plugin: https://wordpress.org/plugins/dw-question-answer/

I tried to switch to other theme and the widgets did not appear though.

Hey, I managed to fix it now. Thanks for your great support anyway!

Could you share with us, what was the source of your problem? (it may be helpful for other users)