Ok, I see.
Yes, delete the iTSec plugin. Let’s rule out the possibility that it somehow got corrupted. There are 2 methods for deleting the plugin.
1. Simply click on the plugin Delete link. This will also delete any plugin data from the database (you will be asked for confirmation). Once deleted, if you wish to reuse the plugin, simply (re)install it. The disadvantage of this option is that after activating the plugin you’ll need to walk through the plugin settings again.
2. Manually delete the better-wp-security folder. To do this either use an FTP program or simply log into your hosting panel.
Then download the iTSec plugin zip file and use an FTP program, or simply log into your hosting panel, and upload/unzip the zip file in the plugins folder. Refreshing the Plugins page in the Admin Dashboard will show the plugin is listed again. Because we didn’t delete any plugin data from the database, the plugin will continue using the old (configured) settings. So no need to walk through the plugin settings again.
No matter what method you choose, let’s hope it activates again without any fatal error. Oh and let’s keep our fingers crossed ??