Can't publish a Hangout app (extension)

Question

I've created a Google Hangout extension app, tested it works privately etc and now I'm trying to publish it. I have followed the instructions here:

https://developers.google.com/+/hangouts/publishing

I've filled in the forms correctly, created the O-Auth client ID, filled out the consent form etc. When I tick the Make this application public tickbox and try to save, a server error message pops up along the lines of:

Server Error
Whoops! Our bad.
Please try again. If the problem persists, please let us know using the "Send feedback" link below. Thanks!
Tracking Number: XXXXXXXXXXXXXXXXXXXXXXXXX
[Send feedback]

I've checked the Chrome console - the request gets a 500 error and in the JSON response I can see:

{"message":"Developer not registered with CWS."}

I have paid the $5 one-off developer fee on the Chrome Web Store and I am the Hangout project owner. I'm not sure what I'm missing here. I need to get this published in the next 24 hours...

Any useful insights? Is there any official support forum for Google+ platform developers?

UPDATE

I was using a Google Apps account before so I've paid the developer fee on a personal account to verify me on CWS, made this account owner of the Hangout project and I still get the same message response.

I believe then that it's basically just broken. Thanks Google.

Parapet

Try to log out and log back in to the account that is CWS-registered. – Hoot

Yep, tried that, no joy. – Parapet

What happens if you try publishing ANY item in CWS itself? Try any sample app from Google. You could also try this support channel, but again, this is for regular extensions/apps. – Hoot

And make sure the Google Developer Console is also logged into with the same user. – Hoot

@Hoot I successfully managed to publish the 'hello-world' app on CWS. I hoped publishing that might somehow fix the Developer Console, but it's still chucking me a server error. >:| – Parapet

I'm using a Google Apps account... could this be it? – Parapet

Probably. Sorry, I'm not familiar with this situation, and so I can't help with that. – Hoot

@Parapet : I've stuck at this same scenario.Did you get any solution? pls help me – Disjunction

This is still an issue. Replicated it on multiple accounts, a G Suite account and regular account. {"status":400,"message":"CWS registration state\u003dnull (Developer not registered with CWS.)"} – Parapodium

@Parapodium I was able to publish an app a couple of months ago. I understand that the UI is buggy as till now it shows the app is private yet it is not. In case you are following the steps correctly, I would suggest opening a new project and try to publish it again. Let me know if it helps. – Longobard

@AdityaC This is an app that was previously public and in use by a client. When I tried to update the project two weeks ago it reverted it back to private. I've tried different projects on the same account, and the same project on different user accounts. I've bought multiple CWS developer accounts. Tried it in different browsers. Tried with a G Suite account and a personal Gmail account. Tried buying an Google Play developer account, because I thought it was possible Google was transitioning concept of a "confirmed developer" to that platform. – Parapodium