As many others, a few of our websites got screwed by iThemes Security "upgrade". We had login issues where we were redirected to homepage.
There issue is somewhere in the database, it gets screwed up with an upgrade. I did not have time trying to figure out the problem, that's for the plugin developers. BUT, I needed to fix sites. So here's how I fixed my sites by resetting this plugin's database.
This is not for the faint of hearts, it requires some technical knowledge to edit your database tables.
BACKUP DATABASE! BACKUP DATABASE! BACKUP DATABASE!
Use phpMyAdmin to export your database. See Google for details or
see this article http://www.techrepublic.com/blog/smb-technologist/import-and-export-databases-using-phpmyadmin/
1. Through FTP or cPanel file manager, go to /wp-content/plugins/
2. Rename "better-wp-security" folder to something else like "better-wp-security2"
3. Plugin is disabled and your admin is back working.
4. Now, the reset. You need to access your database, ideally through phpMyAdmin interface in your control panel (cPanel).
5. If you have many websites, locate your correct database for the website you're working on. You can match database name to the name inside wp-config.php file.
6. Click database name to select and load it.
7. On the right side you will see a list of tables.
NOTE: THIS IS A GOOD TIME TO BACKUP/EXPORT YOUR DATABASE. YOU'VE BEEN WARNED.
8. Delete tables with "itsec" - see screenshot
9. Go to your "options" table, click it.
10. Sort by "option_name" by clicking the header, and making sure you got rows sorted A-Z.
11. Find option_name rows starting with letter I.
12. Look for "itsec" options. See screenshot.
13. Select all of them. If you're at the end of the current page, make sure you delete options and check next page to make sure you get them all.
14. Once you delete these options. Go back to FTP/File Manager.
15. Rename folder back to it's original name "better-wp-security".
16. Login to your UNBROKEN website using normal wp-login.php URL.
17. Go to Plugins and activate this nasty plugin back.
18. It should be fine, you HAVE TO GO THROUGH SETTINGS AGAIN and set it up to protect your WordPress. We deleted all settings!
19. Carry on WordPressing.
20. Still here? Go.
It fixed our homepage redirect issue, but it may fix other issues as well that you might be experiencing. Please be careful and test.