Create process variable "var" of any type. Create Multiple instance sub-process. Set MI collection Input or Output value to "var". Delete process variable "var". [Optional] Try to delete MI collection Input or Output value. Save, close and open process back. Actual result For MI collection Input or Output value: It is not possible to delete it. It is not deleted automatically. When process is opened back, xml editor is opened instead of process editor since the process is broken. Expected result For MI collection Input or Output value: It is possible to delete it (set it to empty value). It is deleted automatically once the process variable is deleted. When deleting the process variable that is used on other places, warning message is shown that it will affect other nodes with the list of nodes names/IDs including. When process is opened back, process editor is open because the process is not broken.