I purchased your extension "Simple Details on Configurable Product", but when I install version 1.2.9 on M2.2.0, I get the following error:
PHP Fatal error: Interface 'Magento\Framework\App\Action\HttpPostActionInterface' not found
in /app/code/Bss/Simpledetailconfigurable/Controller/Ajax/Product/Post.php on line 25
Could you please check and fix it?
The current version 1.2.9 is not compatible with M2.2.x at this time so it caused the issue above.
To solve it, please edit these files as below:
Please check and apply the attachment files on the site and flush the cache.
If you need any help, please feel free to contact us.
We'd like to support you.