Yikes! Sorry about that.
We always recommend having restorable database and file backups as well as performing modifications first on a staging site before modifying anything on your live/production site.
I see you have PHP 5.6+ so that shouldn’t have been the issue.
Please download fresh copies of the latest versions fromĀ https://theeventscalendar.com/my-account/downloads/, delete the existing versions you have installed, and then install the latest versions via wp-admin.
Hopefully this will ensure all is okay. If not, it’s likely there’s a conflict with your theme or another plugin, possibly one that’s trying to integrate with our plugin suite but maybe not doing it in the latest-greatest way.
Again, a staging site is recommended.
Please let me know how this goes for you.