Magento 1.6 Upgrade Errors with Solutions

Magento 1.6 Upgrade Errors with Solutions
Magento 1.6 Upgrade Errors with Solutions

After upgrading to Magento 1.6, You may face some problems like Integrity constraint violation: 1062 Duplicate entry or Error 404 after installation(while home page is OK).

1- “Integrity constraint violation: 1062 Duplicate entry “
Solution:
This error can be solved by disabling the unique indexes check.

In the app/etc/config.xml, change this

SET NAMES utf8

to this

SET NAMES utf8; SET FOREIGN_KEY_CHECKS=0; SET UNIQUE_CHECKS=0;

2. Error 404 after installation(while home page is OK)

Solution:
You will need to do one of two things:
-Refresh catalog rewrites – Admin > System > Cache > Refresh catalog rewrites. If this doesn’t work then >
-Turn off URL Rewrites – Admin > System > Web > SEO > NO

3. 500 internal error after upgraded

Solution:

CHMOD 755 the following:

- magento/index.php
- magento/downloader/
- magento/js/*

Login to Magento and clear your cache

Source: http://www.expertmagentodevelopers.com/blog/magento-1-6-upgrade-errors-with-solutions/