as I started with modelio in the past (version 3.4 or 3.5) I've created BPMN diagrams to document some rarely used workflows for me. At this time there was only one BPMN diagram type available. Meanwhile the BPMN diagrams was been split into two diagram types and the diagrams which I've created was been shown as BPMN colaboration diagrams and so I was able to use the diagrams to remember the old workflows.
But now the workflow was been change and so I must change the related BPMN diagram too --- unfortunately I am not able to change the diagram because it seems to be locked. Is there any way to split the old diagram in the two new diagram types to correct the workflow without creating the diagrams again?
Changing BPMN diagrams 