Plugin not working in category page

Hi

THe pluging works great in main pages or individual blog entry, but in blog category I click on one I recevive this message:

Fatal error: Undefined class constant ‘pt’ in /home/pedrosol/public_html/wp-content/themes/wp-professional102/functions.php on line 258

this is the website:

https://www.pedrosolorzano.es

if you go to a page not a problem: i.e:

https://www.pedrosolorzano.es/coaching/

If you go to a category of the blog (i.e)

https://www.pedrosolorzano.es/category/coaching/

you have the error message

Thanks in advance for your support

https://www.ads-software.com/extend/plugins/testimonials-widget/