CMMN API Broken in 7.11

Hi team,

Ive been using a CMMN case task form from the snippets repository here;

Case Task Form

This worked well up until 7.11. When I use it with a 7.11 springboot build, I get an internal 500 server error and not much detail on the manual start case execution call (see javascript fragment below;

     // Call according REST API
	   $.ajax('/camunda/api/engine/engine/default/case-execution/' + + '/manual-start', {
	         data: JSON.stringify(data),
	         contentType : 'application/json',
	         type : 'POST',
	         success: function (result) {
	            // when successful reload case status to reflect possible changes

This uses the ‘private’ authenticated API. I then used the ‘public’ REST API equivalent and all works fine, however by default its not an authenticated call.

Hence has something changed in the private API? Whats the best way to start a manual activation in an authenticated way?