Magento An error occurred while saving the URL rewrite

Fix An error occurred while saving the URL rewrite, quick and easy fix for this problem. We always recommend making FULL site backups before commencing. This error normally shows up on a Magento 1.4x installation, the fix we found was to simply to re-index the site: Admin -> System -> Index Management -> Select All and Reindex

The line I commented out to actually get the indexer to work and finish was line 285 in app/code/core/Mage/Catalog/Model/Resource/URL.php

Before

Mage::logException($e);
Mage::throwException(Mage::helper('catalog')->__('An error occurred while saving the URL rewrite'));

After

//Mage::logException($e);
//Mage::throwException(Mage::helper('catalog')->__('An error occurred while saving the URL rewrite'));

I hope its work for you.