About 2-3 weeks ago I stopped using phpmyadmin and started using MySQL Workbench. Now, I can't connect to phpmyadmin. I tried connecting from two different computers and from the server. Tried connecting with at least 4 users and root. I am suspecting that this is Workbench's fault. During the time I used Workbench I made some changes to user privileges, but don't remember the specifics. I get "Wrong username/password".
Any thoughts ?
Looks like some of the comments have been deleted, but judging by what's left there was a suggestion for you to check your permissions for your user with hostname localhost, and it appears you did not understand that % is not the same as localhost. Many installations come with several root users, one for host localhost, one for host %, and sometimes a third for 127.0.0.1. This is normal and part of how MySQL handles permissions. TCP/IP connections match %, socket connections do not (they use localhost).
Another thing that's important to realize is that, when using phpMyAdmin, it doesn't matter what client machine you're using; what matters is what machine is the web server, since that's where the requests to MySQL come from. So you can easily get a bit confused if using a remote machine to connect to a web server running on the same machine via sockets to the MySQL server -- even though you're on a remote machine from the MySQL server, in this case it appears as a localhost connection to MySQL.
Anyway, very likely what happened was you were "cleaning up" extra users and removed one that had the opposite host value (either % or localhost); I'd simply recreate your user with the other host. That should clear it up for you.
