Do you have plugins active on the site?
Yes, I know that I have contact form 7, but I’m not sure if I have any others.
I would start with inspecting the plugins via FTP. Find out what you have. This could either be a plugin problem or a problem with your functions.php file located within your theme. I would first start with the plugins though.
I’m having the same issues. The problem is that if we cannot access any of the admin pages we cannot inspect the plugins.
@rohara1977 you need to inspect the plugins via FTP using an FTP client.
http://codex.wordpress.org/FTP_Clients
@ljbluwater
I noticed you are hosted by GoDaddy. See if anything in this discussion has anything in common with your situation. (possible solution)
http://wordpress.org/support/topic/i-lost-access-to-wp-admin-when-i-upgraded-then-i-fixed-things?replies=6
Thank you, thank you, thank you. It worked.
I searched everywhere on these forums to find a fix, how did you find it @claytonjames?
This issue has been resolved!
I’ve sort of been watching the issue in general (Page Not Found after 3.4.1 Upgrade) for a while. I’ve never been able to duplicate the problem on any of my own sites, but most times it seems to be easily fixed by just doing a re-install or a manual upgrade. After looking at a handful of similar issues here in the forum, a lot (not all) of the folks reporting this problem are hosted on GoDaddy.
I want to emphasize that I am in no way implying that it’s a Godaddy related issue; I simply wanted to point out that for anyone who is hosted on GoDaddy, and experiencing the same issue, the information in the thread I pointed you to seems to be a fairly successful method of resolving the issue for Godaddy customers so far. I would think that a manual re-update of WordPress would probably have a similar success rate, but mileages do vary! 🙂