Fatal Error activating plugin

Receiving this error in the dashboard after deactivating plugin via ftp and trying to reactivate it:

Plugin could not be activated because it triggered a fatal error.

Parse error: syntax error, unexpected ‘[‘ in /home/content/69/12063869/html/blog/wp-content/plugins/above-the-fold-optimization/admin/admin.class.php on line 1118

WP 4.8.2 All plugins up to date, no recent changes except for updating this plugin.