I'm aware that this question has been asked previously, even repeatedly, but I find no clear answer in either of the posts I can dig up. These, for example:
How to log in to SO using a Google Apps account
How do you delegate your OpenId to Google Apps
Now, to the real question. When I click login, I get a big google logo as a choice. I click it and get to a standard google login page. Logging in here with my domain name however fails.
So in the second of the above posts I find this link:
which I modify for my domain, obviously. Entering that adress into the "manually enter your openid" or into the URL field both direct me back to SO with:
"Unable to log in with your OpenID provider: Error occurred while sending a direct message or getting the response" which is completely different from a random URL that returns:
"No OpenID endpoint found."
If there's a question somewhere which provides more details on this error, I apologize for not finding it, but I have spent around an hour on this, with lots of searching, and I feel really stuck.