Editing StateChart Scxml crashes Qt Creator

I am developing a state chart using scxml tool in Qt creator. So just for this bug-telling story, in this case, I have created just two states A and B. Whenever I take a transition arrow from A and end it to state B, everything goes well. So now to remove the trail of the line, a user has to Right-Click somewhere on the chart. when I Right-click on any part of the transition line that I just created, Qt Creator crashes.