Cannot add/change images in Carousel

Hello all, I’ve been trying to modify the images of a Carousel and it gets stuck. I have close and open the browser and also restarting the laptop but I cannot.

I have not added any code or something else which can cause this issue.

Please see this page in the section: Aplicaciones Residenciales, and you will see some errors

http://energycorp.com.mx/servicios/

I was thinking that I should have a kind of plugin update but there is not anyone.

Besides, I am working directly to the Main Theme, so, I am not sure if upgrading the full theme will affect all the work. what should I also do if I want to upgrade the Theme but I am working directly to the main Theme?

Best regards..!!..