JQuery can’t be loaded in the application (server returns 404), causing multiple features to not work, like Fetching user options and registering an application.
In the screenshot, the text “Fetching user options, please wait…” stays there indefinitely.
Selecting “API key” option has no effect.
This is probably caused by the file https://developer.companieshouse.gov.uk/javascripts/jquery-1.8.0.min.js not being available and the subsequent errors shown in the console.