Fatal error when activating plugin

Hey all,

this plugin looks like a godsend for someone using bcrypt and wanting something more recent than…3 years ago. I’m trying to hook up a wordpress (4.7 currently) to an external DB. When I activate this plugin I get the following:

Parse error: syntax error, unexpected ‘[‘ in /data00/html/portals/<REDACTED>/wp-content/plugins/external-login/options/add_plugin_options_links.php on line 4

I don’t know how a syntax error bracket could get through, and I don’t think that’s what it is. The file referenced by the error looks like it’s trying to add a link to the plugin settings. I’m currently using the responsive theme, and wondering if editing theme HTML is messing it up.

Here’s the code snippet that’s erroring:

function exlog_plugin_action_links( $links ) {
    $links = array_merge( array(
        '<a href="' . esc_url( admin_url( '/options-general.php?page=' . EXLOG_PLUGIN_DATA['slug']) ) . '">Settings</a>'
    ), $links );
    return $links;
}

Has anyone else run into this problem? Can’t even activate the plugin to try other stuff!