UIbulder does not want to connect

what folder?

Does the uibuilder node's library tab show that you have the correct versions installed? If so, do a ctrl-f5 to force reload your ui and see if you are still getting the same errors.

If so, go to the networks tab and find out for each 404 line what it is trying to load.

Also, please share the content of your main index.html file so that I can check it is correct.