I had a separate log in account for mathoverflow. Now, I'm unable to log in into that. I see only options of logging in using google, facebook, stack exchange etc but no option of logging using mathoverflow. How can I access my old account?
What can I do?
This is a simple issue that can be quickly rectified by following the steps below:
Go ahead and create a new account using whatever authentication service you were using previously. Make a note of the profile URL - you can get to the new profile by clicking on your user name at the top of the page. Keep this handy.
Locate your original profile URL, if you don't already know it. You can do this by going to the users page and entering your user name. Keep this handy as well.
Contact Stack Exchange and provide them both links, and indicate that you can no longer access your account and have made a new one.
Wait for a short while, you'll receive a reply indicating that you can now access your account. We try to process these as soon as they come in during the transition and we have overlapping coverage in many time zones.
Please, use the link to contact the team directly as that's where they're monitoring for requests to fix this issue. If you post here, it might be a while before someone from the team sees your request.
Why did this happen?
This happened because your OpenID provider is now returning a different email address during authentication than it did when you originally registered, so the system does not recognize you properly. This is why the system is asking if you want to create a new account.
How do you fix this?
By asking you to create a new account to merge with your established account, we ensure that you'll log in properly when either email address is returned during authentication. Once done, it will be as if this never happened, and no remnants of the temporary account you created for merging will remain.
You can just use the "click here to recover your account" link on the login page. You should then receive an email with a link to a form to set a new password. Afterwards you should be able to log in by choosing "log in with Stack Exchange".