Serious problems with 4.6+

I am having serious problems upgrading to the latest versions (or any version 4.6+) of Event Tickets. It is causing numerous problems on my site. I created a mirror development site, deactivated all other plugins and enabled the default Twenty Seventeen theme to rule out conflicts with custom themes or other plugins.

When both The Events Calendar plugin and Event Tickets plugin are active at the same time, the following issues are observed:

The WordPress Media Library does not function properly. Sometimes, it will only load the top title “Media Library” and the “Add New” button but nothing else. Other times, it will load the top bar of the media library but the circular ajax spinner just spins and spins and none of the media library items appear, and the browser console displays an error that reads:
POST: [site url]/wp-admin/admin-ajax.php ERR_INCOMPLETE_CHUNKED_ENCODING

Attempts to activate or deactivate plugins produce a browser error screen that reads “This page isn’t working properly” with the error code ERR_EMPTY_RESPONSE.

The main plugin menu screen does not load fully. It will cut off before all of the content/code has rendered. Where it cuts off doesn’t seem to be consistent.

The Dashboard screen does not load, just displays a blank white screen that looks like a PHP error but registers nothing via debugging or in the error log.

Deactivating either one of these plugins so that they are not active simultaneously seems to resolve the issues noted. However, when they are active simultaneously, the problems occur.

I have not experienced any of these issues with the 4.5+ releases, but the 4.6+ releases cause problems. I have rolled back to the last release in the 4.5 series of releases on my production site until I can get this sorted out on my mirror development site. Any insight you have would be appreciated.