Uncaught TypeError: Cannot set properties of undefined (setting 'self')

[jesjack]

flowchart.parse.js:340 Uncaught TypeError: Cannot set properties of undefined (setting 'self')
at Object.s [as parse] (flowchart.parse.js:340:1)
at btn.onclick (main.html:27:39)
at window.onload (main.html:122:23)

[cdfmlr]

@jesjack would you mind to provide an example input code so we can reproduce this issue?