Editor crashes when changing artboard in code

[BitBarrel]

When commenting and un-commenting the following code, the Unity editor crashes:

Change from this:

// m_artboard = m_file.Artboard(0);
// m_stateMachine = m_artboard?.StateMachine();
m_artboard = m_file.Artboard("Artboard 1");
m_stateMachine = m_artboard?.StateMachine("State machine 1");

To this (and vice versa):

m_artboard = m_file.Artboard(0);
m_stateMachine = m_artboard?.StateMachine();
// m_artboard = m_file.Artboard("Artboard 1");
// m_stateMachine = m_artboard?.StateMachine("State machine 1");