Not all of us are dev's. There are many apps out there that provide both an easy upgrade, and a strong defense. We know because we have used them and upgrades are secure and seamless. These Abantecart upgrades have become intimidating and that should not happen. We just want to have the best products to present to our customers.

 Agree.  Feel free send us donations. This project alive because of you and code is free.

this sounds so wierd.
Upgrade script works as chain.
1. step - running SQl upgrade script (database modification)
2. running php upgrade script.
3. replacement of files with new (including file public_html/core/version.php)

If you see version 1.4.2 in the footer of your admin side, this means previous steps was successful.

Do you have some errors in the error log?
Also you can seek some records in the install/upgrade history table.

Please give us more details.

probably same issue can be with table settings

CREATE INDEX `ac_settings_idx` ON `ac_settings` (`value`(333) ASC);

Hello,

I just wanna know if it's possible to do something to embed a specific html block with a unique url link to share outside of website in 3rd parties webpages and apps.
 
is that possible?

Yes, in theory:
1. create your own controller, let's name it myBannerBlock. As example you can get method "main" from public_html/extensions/banner_manager/storefront/controller/responses/extension/banner_manager.php.
The main function of this controller to send piece of html (tpl-render of ready html-content of block) by request parameters.
2. Then create new html-banner. Get it's banner_id.
3. Insert into table url_aliases data, where `query`  =  'banner_id=123&format=html' and `keyword` = 'some_unique_your_seo_keyword'.
4. Then open browser and put url https://www.yourdomain.com/some_unique_your_seo_keyword

It's a good idea to extend functionality our native banner manager extension. Feel free to donate us for this feature :-)

looks like you forgot ssl:/ as protocol in the settings.
See example here https://abantecart.atlassian.net/wiki/spaces/AD/pages/7372837/Mail+Settings

you should to run sql queries manually via phpMyAdmin.
Regarding error i guess you should to start since line 1091
https://github.com/abantecart/abantecart-src/blob/master/public_html/install/abantecart_database_upgrade.sql#L1091

Do not forget to replace table prefix with yours before

Paypal Commerce extension do not have a management of your Paypal buttons on checkout form. These buttons loaded from their API, it's a third-party code.
So you should to ask their support team hot to enable venmo button inside your merchant account.