I keep running across a frustrating and annoying error when trying to edit sequence diagrams.
Supposing I have sequence diagram like this:
And I want it to look like this, with Message2 starting from the execution specification resulting from Message1.
I try to drag the beginning of Message2 to the execution specification above it on Lifeline2, and I get the following error message: "Cannot move an Execution Specification to its target."
As far as I know, this is a perfectly valid thing to do, and this use-case occurs regularly when modifying/editing sequence diagrams. It makes it very difficult to modify large sequence diagrams as it forces either deleting and recreating messages, or moving portions of execution to a "dummy" lifeline temporarily.
So my question is: Is there a reason for this error? If not, can it be removed for this use-case?
Product: Astah Professional