Magento Admin login kicks me out back to the Admin login

Question

After I enter my username and password and click \"Login\" it sends me back to the Login page with NO error messages. The URL changes to include a session key and that\'s it

Answer 1

I just encountered this problem on one of my servers (not a localhost installation). Turns out the system account was over quota, so I presume Magento was unable to create the necessary temporary files. (I noticed this when trying to create a directory on the server over ssh.)

So... maybe check to make sure the account under which Magento is running isn't over quota on your server? At the very least, it might not be a Magento problem directly.