Hi,
I believe this error is generated on the JS side.
One alternative is to use the approach described in this post, except that each node of app.layout tree has to be parsed to json using the self.to_json_plotly() method individually… So, in principle, this could be quickly implemented with a recurrent function.
Another option is to use to_json_plotly from plotly.io.json, which (I believe) will convert the entire layout in a “JSONifiable” string (json.loads transforms to dict). You will again need some recurrency to find ["props"]["id"] for each component where id exists.
There might be a better “builtin” method to do that, so I hope someone more knowledgeable on the Dash internals will jump in this thread. 
Hope that this helps in the meantime!