CKEditorError: observable-bind-to-parse-error. How to debug?

Hi,
after running Yarn build I got js/build/plugin.js. But there is an errorckeditor5.js?rzx0h0:427 CKEditorError: observable-bind-to-parse-error.
It comes from

 // Bind the state of the button to the command.
      buttonView.bind('isOn', 'isEnabled').to(command, 'value', 'isEnabled');

and I really don't know how to debug myplugin.js file?