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 “
This error can be solved by disabling the unique indexes check.
In the app/etc/config.xml, change this
SET NAMES utf8
SET NAMES utf8; SET FOREIGN_KEY_CHECKS=0; SET UNIQUE_CHECKS=0;
2. Error 404 after installation(while home page is OK)
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
CHMOD 755 the following:
- magento/index.php - magento/downloader/ - magento/js/*
Login to Magento and clear your cache