Topic: Javascript:void(0) error on theme options

I just upgraded WordPress to 5.5.3 and I had problems with a previous version of Legenda. So then I bought the most recent version 4.3.2 in order to have my backend working again, but the problem persist.
The problem is that I am getting javascript:void(0) error when clicking on any of the buttons of the ThemeOptions.

The problem also appears in other parts of the backend, like when trying to add Inventory data to the products, I click on the buttons of that menu and nothing happens. And the notification banners show up in the middle of the screen and it’s all messed up.

Also the option to order products on the woocommerce backend listing is not working… I used to drag and drop products to change the order they will show up on the store.

I need to use the backend of my site urgently and change some theme options. Please help!!!

Thanks!