Thanks for your feedback!
Could you please take a look at the plugin instructions or the support forum before leaving a negative review? There was a recent redesign of the www.remarpro.com Plugin Directory that has basically hidden the instructions (they’re still in the readme) so I can’t blame you for not finding them! To make it easier I’ve pasted them into this sticky forum post.
The plugin requires the PHP mysqli interface be enabled to support SQL transactions. This is explained in the documentation. It’s a one-line edit to wp-config.php to enable this, and then the plugin will activate.
This error message is one I created to let you know what the problem is, so that you can configure WordPress to use mysqli. I just updated the plugin to provide more information in this error message so that hopefully it will be more useful to the next person.
The old PHP mysql interface that your WordPress install is using is not secure and was officially deprecated by PHP with version 5.6. It lacks support for transactions and rollback and can lead to loss of data integrity, so you should definitely enable mysqli — whether you want to use my plugin or not. PHP versions 7.0 and later only support mysqli.
