Fatal error from subscribe by email plugin?

After updating the subscribe by email plugin today, I got a fatal error and cannot access the site:
"Fatal error: Call to undefined function get_blog_details() in /home/content/79/8499579/html/home/wp-content/plugins/subscribe-by-email/inc/settings.php on line 116"

Line 116 reads:
$blog_details = get_blog_details();

I posted this in another similar thread from 3 months ago, but realized it is a slightly different issue, as the fatal error has to do with a completely different line, and has since been resolved.

I realize that if I go into my FTP and delete the plugin, I will have access the my site again; however, if I re-install and activate the plugin again, the same thing happens, and I'm not sure how to fix it. So if anyone else is experiencing this problem and you know what to do to fix it, please do let me know. :slight_smile:

I have previously had issues with the plugins being incompatible with the theme I'm using, and I did receive fatal errors, however, the error was in the theme file, and not in the plugin file as seems to be occurring now.

Thanks for reading and/or helping!