We recently migrated our Multi-domain magento setup from a shared host to a dedicated server.
All is working fine fronted, but when I try to go to the admin section I get a 404 error on anything after login.
It seems to work if I remove index.php from the url but then as soon as I click on another link in the admin section it 404's again with the index.php back in the URL.
-- You need to go your server directly and do this via SSH/ FTP
You have to delete the following file
app/etc/use_cache.ser
If you get an error after that like
Notice: Undefined index: 0 in /srv/www/vhosts/javra.com/htdocs/munchad2/app/code/core/Mage/Core/Model/Mysql4/Config.php on line 92
Then go to your Database Management.
_
SET FOREIGN_KEY_CHECKS=0;
UPDATE `core_store` SET store_id = 0 WHERE code='admin';
UPDATE `core_store_group` SET group_id = 0 WHERE name='Default';
UPDATE `core_website` SET website_id = 0 WHERE code='admin';
UPDATE `customer_group` SET customer_group_id = 0 WHERE customer_group_code='NOT LOGGED IN';
SET FOREIGN_KEY_CHECKS=1;
Some thing strange happens with the cache when you move the databases from one server to another so it seems like you need to clear it out.
After migration from www.domain1.com/magento/ to www.domain2.com/magento/ I was getting 500 Internal Server Error. So I just renamed my .htaccess to htaccess.txt. And my frontend started working fine, But at Backend http://www.yourstore.com/admin/ I was getting Same 500 Internal Server error.
After trying many option suggested online nothing worked for me and after that I tried to access admin via following URL and voilà worked perfect, Hope this help others.
Try to access as this > http://www.yourstore.com/index.php/admin/
