/_layouts/15/OAuthAuthorize.aspx no longer working

Hi there,

    Just posting here in case anyone else has been able to get /_layouts/15/OAuthAuthorize.aspx to work lately?  A few days ago when trying to Auth Client ID's an error started occurring:

Sorry, something went wrong
There is no claims identity. Please make sure the web application is configured to use Claims Authentication.

URL used was in this form:

https://mycompany.sharepoint.com/sites/site/_layouts/15/OAuthAuthorize.aspx?client_id=<guid>&scope=List.Read&response_type=code&redirect_uri=https://localhost:3456/redirectaccept.aspx 

Have not been able to get any of our Client ID's or tenants working.

There seems to be some other people experiencing the same thing: 

 - sharepoint - Cannot set up OAuthentication - Stack Overflow

 - OAuthentication with office 365 Failure :There is no claims identity. Please make sure the web application is configured to use Claims Authentication - Microsoft Q&A

If anyone has a solution or a workaround, please let me know.

Cheers,

   James.