Really sorry to hear about this @Frank – this NOT normal behavior and there are no reports of similar behavior at this time, so it sounds like something is conflicting on your site.
Are you able to access your wp-admin now? I’m not sure because you said you were unable to, but then also mention having done some plugin conflict testing.
If you can access your wp-admin, please deactivate Events Calendar Pro and then share your system information with us. Here’s how to do that → https://theeventscalendar.com/knowledgebase/sharing-sys-info/
Then, see if any errors pop up on your site if you head to your site’s wp-config.php file and change this line of code:
define('WP_DEBUG', false);
to this:
define('WP_DEBUG', true);
That will display PHP errors if any exist, which might be quite useful here.
Once you’ve made this change, re-activate Events Calendar Pro so that your site breaks, and see if any PHP errors are there on the white screen. If so, copy and paste the entirety of these errors and share them with us here.
Thank you!
George