Can’t Login After Auto Upgrade to 2.9.1 (two blogs, one site)

Hello,

I have looked around and tried others’ suggested solutions, but I’m getting nowhere.

I have two blog installations on one database. I used the auto-upgrade for my main site/blog and had no problems. I then did the same for the second installation/blog and could not login.

The update appeared to work, but I could not/cannot login.

Now, I cannot login to either blog. I have reset the passwords, both automatically generated and manually through phpMYADMIN, cleared cache and cookies, renamed plugins folder, etc. PLEASE HELP!!!