Magento – Redirect install(Downloader) wizard but already installed

The row is created when you have an entry inside of your config.xml. If no setup file exists (or it is in the wrong place) magento just creates the row in the core_resource table and doesn't call any script.

This is a problem if you later add a install-script, which is never called, because the entry already exists.

So first write an install script, then add the setup to the config.xml and later add upgrade-scripts if needed,

If you don't have a backup (e.g. in git) you're in a quite difficult situation.

Try the following:

• Delete the cache (var/cache/ if you don't use something else as the cache backend).
• Add the local.xml template: https://gist.github.com/thebod/9001682 to app/etc/
• Clean your browser cache (to prevent redirects cached by the browser)
• Open the /install again and do the installation
• You should now have a working local.xml again and the shop should work

But note: Because the local.xml is gone the encryption key is gone as well, that means every encrypted configuration option, credit card, etc. can't be decrypted anymore! Cracking the encryption key would work, but requires some knowledge about crypto, so that would probably not an option for you.