Here is the process required to activate the bug :
1/ I create a diagram thanks to the activity modeler
2/ I create a user task
3/ I add a form to this user task with a type ENUM and two values ("approve" or "refuse" for instance)
4/ Then I save the diagram
5/ I deploy the process and start this process
BUG : when the user open the task to execute (after the step 5), the two values from the combo list (type ENUM) disappear.
In fact when editing a process in the activti modeler it seems to change the XML corresponding to the process by deleting the XML code of the type ENUM. This bug was known from the past two years (see it in jira's forum). Is there a solution to fix it now ?