Blank page in popup when trying to authorise token

[Moult]

This is the URL the popup has after I click the yellow Click here to authorize application button. It just shows a blank white page.

https://9-volt.github.io/bug-life/redirect.html?code=e952a2110ce2b62df88f&state={"client_id"%3A"689dea3122f7c6cd4dba"%2C"network"%3A"github"%2C"display"%3A"popup"%2C"callback"%3A"_hellojs_94ut7y3r"%2C"state"%3A""%2C"redirect_uri"%3A"https%3A%2F%2F9-volt.github.io%2Fbug-life%2Fredirect.html"%2C"scope"%3A"basic"%2C"oauth"%3A{"version"%3A2%2C"auth"%3A"https%3A%2F%2Fgithub.com%2Flogin%2Foauth%2Fauthorize"%2C"grant"%3A"https%3A%2F%2Fgithub.com%2Flogin%2Foauth%2Faccess_token"%2C"response_type"%3A"code"}%2C"oauth_proxy"%3A"https%3A%2F%2Fauth-server.herokuapp.com%2Fproxy"}