Fatal PHP Error

Hi,

I’m running Elementor, and this plugin is causing problems. If I try to save a page edit in Elementor where the shortcode for this plugin is present, I get the following error:

[09-Dec-2019 16:52:09 UTC] PHP Fatal error: Cannot redeclare OWAC_check_date() (previously declared in /home/xxxxx/public_html/wp-content/plugins/availability-calendar/public/includes/frontend.php:25) in /home/xxxxx/public_html/wp-content/plugins/availability-calendar/public/includes/frontend.php on line 25

If I disable Availability Calendar, the page saves fine.

Any idea why this error is occuring. I’m on PHP V7.1 right now.

Thanks

Bob