Bug with most recent update: Error from WooCommerce Log

Thanks Long, Just to clarify do I need to add:

if (class_exists('MB_ADMIN_COLUMNS_POST')) {
    class SHS_MBAC extends  MB_ADMIN_COLUMNS_POST {
    }
} elseif (class_exists('\MBAC\Post')) {
    class SHS_MBAC extends  \MBAC\Post {
    }
}
class SHS_Member_Link_Columns extends SHS_MBAC {
    public function columns( $columns ) {

to the custom.php file I make or to the functions.php file?

Also, in the custom.php file will all me pre-existing admin columns be automatically created with this code?

Or do I need to add the following code for all my pre-existing custom admin columns:

$this->add( $columns, 'column_id', 'Column Title', $position, $target )

If I do, what do what do I replace the $position and @target variables with?

Hi Long, I think where I'm confused is that I am not using standard wordpress class like in the example.

I've created a custom post type called "Donor" and I've created custom taxonomies. The custom taxonomies are what is being displayed in the admin columns see the attached image.

Could you give me an example the code based on the custom taxonomies I've created in meta box:

https://ibb.co/VSKpm6J

It conflict appears to actually come from MB custom Post Type, because If I decativate that and reload my checkout page the "place order" button works. But my whole website is built around the custom post type.

I have the same issue when I switch to the default "Twenty Nineteen" Theme

I did the debug in Twenty Nineteen. I think it's an issue with my Custom Taxonomies, more on that later. Also, I've deactivated most of the features in Meta Box AIO and Registered Post Type & Registered Custom Taxonomies in the Theme's function PHP file. I did this for both my standard theme and the Twenty Nineteen Theme:

1) Debug Mode: https://ibb.co/smT5Wkh

2) Debug Mode Search & Filter Pro Deactivated: https://ibb.co/KLR2ChW

3) Debug Mode Back to my Normal Theme: Produces the same error as the Twenty Nineteen Theme

I am adding 6 custom taxonomies. 5 of which are being used in Search & Filter Pro. When comment out 1 of the taxonomies used in Search & Filter Pro, the Proceed to checkout button reappears.