This message appears because the file you are attempting to import/export is larger than 2GB and you are using 32-bit PHP.
Files larger than 2GB are not supported by 32-bit PHP.
You can either:
1. (Recommended) Install PHP 64-bit. PHP 7 is the first official version of PHP with 64-bit support for Windows, and it is available for download from PHP’s official website: http://php.net/downloads.php
– or –
2. Limit the size of your backup.
If you need help reducing the size of your backup, please contact our support team at firstname.lastname@example.org.