Hello,

So the out-dated theme!

1. Recreate your header in the Header builder: https://xtemos.com/docs/woodmart/header-builder/

2. Deactiate and delete the plugins mentioned here: https://xtemos.com/docs/woodmart/faq-guides/3-x-4-0-migration-guide/

4. Deactivate all the plugins not related to the theme, leave these ones only:

Slider Revolution
WPBakery Page Builder
Woodmart Core
Contact Form 7
MailChimp for WordPress
WooCommerce

4. Save the content of all the widgets in all the sidebars if you have any HTML code or texts to your PC and make screens what and where should be to restore.

5. Update the theme.

Considering the fact you have not updated the theme for ages you may lose some of your settings and you will have to recreate theme.

Best Regards