Directory Programming .NET

It's all white and just says 'Active Directory Federation Services' with a UserName and Password field and a Submit button, the top left corner has:

https://[the url of federation server]/clientlogon.aspx
CollectInitialCredentials

What could this mean?

In ADFS, you don't see the names of the actual forms, only the URL with the query string (like https://fedsrv/adfs/ls/?wa=signin1.0&xxxx), so if I had to guess, I would say that something is configured incorrectly somewhere.  It also looks like someone might have been doing some experimentation with customizing the forms-based login page.

Is this not your FS or something?

Half of the setup is our FS the other is the account partners, the change came as soon as they reconfigured their FS as a proxy.

The proxy does forms auth by default.  Normally, the expectation is that if you use the proxy and forms auth, you also customize the form to make it look pretty.  I'm not sure what some of the weird text is about but the blank white is how the default forms look out of the box.

I assume that it actually works (they deployed the proxy right) and it is just the cosmetics that are not good.

You should also only see this when logging in to their account store. You should not see this when authenticating users in your store.