Jigsaw in IPython does not generate nor run code (Blockly)

[Carlo Alessi]

I am trying to use the notebook Jigsaw in IPython.ipynb. However, these are the problems I am encountering:

1. executing %jigsaw Python --workspace workspace1, I get the browser console error

VM168:106 GET http://localhost:8888/workspace1.xml 404 (Not Found)).

On the Blockly interface, I get the following browser console errors...

2. clicking the button Run

VM48:84 Uncaught TypeError: Cannot read property 'notebook' of undefined
  at HTMLDocument.document.jigsaw_generate (eval at evalInContext (index.js:8), <anonymous>:84:39)
  at HTMLButtonElement.onclick (workspace1.html?_xsrf=2|afe048d7|55c8173e907ca90944da77eacd067a53|1582811607&1583148546111:400)

3. clicking the button Generate Python Code

Uncaught TypeError: Cannot read property 'parentNode' of undefined
    at HTMLDocument.document.jigsaw_get_cell (eval at evalInContext (index.js:8), <anonymous>:113:32)
    at HTMLDocument.document.jigsaw_generate (eval at evalInContext (index.js:8), <anonymous>:80:43)
    at HTMLButtonElement.onclick (workspace1.html?_xsrf=2|afe048d7|55c8173e907ca90944da77eacd067a53|1582811607&1583148546111:401)

4. clicking the button Clear Cell Output

Uncaught TypeError: Cannot read property 'parentNode' of undefined
    at HTMLDocument.document.jigsaw_get_cell (eval at evalInContext (index.js:8), <anonymous>:113:32)
    at HTMLDocument.document.jigsaw_clear_output (eval at evalInContext (index.js:8), <anonymous>:125:35)
    at HTMLButtonElement.onclick (workspace2.html?_xsrf=2|afe048d7|55c8173e907ca90944da77eacd067a53|1582811607&1583148516824:402)

PS: using Google Chrome with the Ignore X-Frame extension installed.