Magento

If you did a manual upgrade and you are getting an Error 500, this is your fix. 

If you update via Magento Connect it will make the changes using your user. However if you do a manual extraction of the files and folders you will have replaced most of your existing files with the new versions that were made by Magento and have their user as the owner not yours.  The reason you are getting error 500 is because the owner and group that those files belong to is magento’s 1082.  To verify that this is the case navigate via SSH to the root of your magento install and type:

If you see 1082 in the 3rd and 4th columns then you know this is your problem.  OK FOR THE FIX FINALLY:
While still in the root of your magento install (where index.php is) enter these commands (replace username and groupname with your username).  If you do not know what your username or group is, you can verify this information simply by listing the directory with the first command I showed you: “ls -l” Not all of them will say 1082, existing files that were not overwritten will still show your own credentials.

If you are still getting an Error 500 your permissions are too far open and apache is refusing to give up all its honey to the world.  To fix this enter these commands once again at the root of magento install:

If you are stilling getting an error 500 you may have managed to change your permissions on your web folder.  It depends on your setup, it may be called public_html, or www.  Also if you have magento in a folder named magento you may have fudged the permission on this.  Just navigate to the directory where this is stored (if you are not sure try cd ../ then type ls to see what is there.  Do it again if you have everything in a magento folder to get to the root of your web folder.  Once you are in the right directly use this:

I’d like to add that there is a very simple way to avoid having the Magento files owned by user and group 1082. When extracting the Magento archive, don’t do it as the root user but as a regular one. This way all files and folders will be owned by the user and you won’t have to chown any files and folders

Very true I should have mentioned that.  However my hosting company only gives root ssh access.

veracious - 15 February 2011 11:40 PM

If you are still getting an Error 500 your permissions are too far open and apache is refusing to give up all its honey to the world.  To fix this enter these commands once again at the root of magento install:

find . -type d -exec chmod 755 {} \;
find . -type f -exec chmod 644 {} \;

Ok now check if your site works!
These are a good idea too although it isn’t the cause of your error 500:

chmod o+w var var/.htaccess app/etc
chmod 550 pear
chmod -R o+w media

If you are stilling getting an error 500 you may have managed to change your permissions on your web folder.  It depends on your setup, it may be called public_html, or www.  Also if you have magento in a folder named magento you may have fudged the permission on this.  Just navigate to the directory where this is stored (if you are not sure try cd ../ then type ls to see what is there.  Do it again if you have everything in a magento folder to get to the root of your web folder.  Once you are in the right directly use this:

chmod 755 magento

and similarly for the website root the example is:

chmod 755 public_html

Thanks for the idea about file permissions.  I downloaded a script I’ve used multiple times from this site: magento-cleanup.php

After running the script again it cleared up my 500 errors.