By doing many useful changes magento is improving a lot in the current competitive market. As a part of that Magento released the latest stable community version 220.127.116.11 on 5th July 2012.
Now it’s time for magento store owners to upgrade their store to latest version to get the maximum advantage of new functionalities.
To upgrade the magento store you can follow the steps given in the below link.
Now let’s come to the main topic. Just before a month I had a task to upgrade magento to 1.7. To do that task I followed the proper steps. But after upgrading I opened my site and it was giving “404 Error” on each page of site.
At that time I was surprised and confused about what happened with my site.
Then to solve that problem I searched the web and found the cause of problem and solution of it that I have discussed below.
Many times while doing any operation with magento connect manager such a 404 error encounters and our site get stopped working.
The cause of that problem is incorrect folder permission.
To solve that problem just download the magento-cleanup.php file from here, put it in your magento root folder and execute it.
Once you executed it you can see the list of messages that magento cleanup has reset the folder permission.
And if you have “maintenance.flag” file in your magento root folder then delete it.
Now open your site and see the result.
Also refer the under given link to get knowledge about some nasty issues which can occur after upgrading magento to 1.7.
Hope this will help you.