Don't specify a custom js for the cme_js property so the default is loaded.
login to oscar and simply check the console output you will see that /js/custom/default/global.js has failed to loaded.
It would be expected that a 404 error not be generated
The file attempts to load but then fails with a message:
Then the file fails to load because it doesn't exist.
This will occur everytime the appointment screen reloads.