Bug: Copy/Paste From One Nested State to Another Nested State Causes Unhandled Exception

[justin0mcateer]

Description

When trying to move a set of states and transitions from one parent to another, I am frequently seeing unhandled exceptions that the source of undefined does not exist. This unhandled exception causes not only the paste to fail, but the editor panel (not the entire UI) is then non-responsive and the page must be refreshed to continue. In the worst case, if you cut rather than copy, whatever was cut will be lost forever.

Expected result

The states and transitions should be pasted into the new parent state. If there is some problem with a particular reference because not everything was copied, dropping some transitions would be better than crashing.

Actual result

In the vast majority of cases, there is an unhandled exception and the editor panel becomes entirely unusable and the page must be refreshed. The cut-paste workflow results in data loss.

Which browsers are you seeing the problem on?

Chrome

Additional details

Apparently, you can easily accomplish the same by going into the 'Details' panel, select the 'parent' drop-down and changing the parent. That approach works without issue, too bad I didn't notice it earlier...