WordPress - can´t login with the admin account after restoring MySQL DB

Question

I've got a Wordpress blog hosted on Linode under Cherokee web server, but the performance has been problematic the last weeks and I'd like to give a chance to Nginx.

So I've made a DB backup of the current site, setup a LEMP platform, installed wordpress, and the "new" wordpress, with no articles (yet) on it works as expected.

But when I restore the mysql database from the current blog, the site shows a blank page. I've copied all the wp-content directory onto the new WordPress directory, and I've tried to disable all the plugins, but nothing changes.

In fact, there's an even more important problem: I can't login with my old admin/pass account, that should be inherited from the old database. In fact when I do a SELECT on the wp_users table, everything seems to be fine (equal to the old installation), but I can't login no matter what I do.

I've even tried to change the admin password with an UPDATE and the MD5 function under mysql, and although the table is updated, the pass does not work either.

So all I get is a restore I can't access to (an neither my readers can) :(

Answer 1

The issue causing the blank page is likely that your old install used a theme other than the default, and since you haven't copied wp-content over, it's looking for a theme that doesn't exist. I find that with importing an installs database, this happens rather than it just reverting to a default theme, as it does when you delete the current theme on an active install.

Something you may consider trying to get around the login problems is doing a WordPress export (Tools -> Export). This will work if you don't have much media attached to your current posts, as it will only copy post contents, and not attachments. Import that export to a fresh WP install on your new platform and both problems should be solved.

Answer 2

Could be a plugin problem; rename your plugin folder to "oldplugins" and see what happens.

Reupload fresh copies of all WO core files/folders, except for wp-config.php and wp-content

Could be a permissions problem; check http://codex.wordpress.org/Changing_File_Permissions

And: did you change DB table prefixes?