Error page produced instead of quote page

When I click on the tag or category for the quote I get taken to an error page. When I search for quote in search form, it is found, however when clicking on the page link displayed I get the same error message.

Site is https://www.psychewizard.com and the two widgets concerned are at the bottom of the right sidebar.

Any ideas please?

Thank you.

https://www.ads-software.com/extend/plugins/quotepress/