WP Admin pages giving 404 error

Hi there,

I have an ecommerce store with around 53 live plugins. The site developed a few problems a few days ago and was knocked down with a 503 error. Renamed the plugin folders and found that the site is back after renaming the wordfence plugin. Finally got rid of the plugin and related files as told by the plugin authors and can log into the site using wp-login.php.

Here is the issue.

site/wp-admin goes into endless loop and will not load. Finally, logged
into the site using wp-login.php I can see the top admin bar but as soon as I click on any page and the url structure changes to site/wp-admin/page etc, again 404 page.

Looked at the htaccess and everything is fine there. If I delete it, the site goes down. Interestingly the frontend is working fine which was knocked out a few days ago with the 503 error.

Given this is a woocommerce site, not being able to do anything is really frustrating and I am trying my best to find a solution. It does seem to be a wordpress problem as even after deleting the plugin folder did not help. As soon as the wp-admin word appears in the addressbar, the pages are redirected to 404. Even if I try to see the source for the wp-admin page.. it goes down with a firefox redirect message. Very strange indeed.

Any help will be very much appreciated. Thanks.