Spotify not connecting to google assistant

[NickPembo]

Hey, 

For the past month I have been trying continuously to link my spotify account to my Google Assistant on my Android Phone, when I click "Okay" on the sign in page it takes me to this url: https://clients3.google.com/cast/auth/3p/done?status=error. Thus I knew I had a problem, If anyone would be able to solve this that would be fantastic.

Thanks,

Nick.