升级完Magento，就应该重新生成吧，但是却出现了Product Flat Data Index process is working now. Please try run this process later.这个错误，时而还500一下，可把人弄糊涂了，不过还好啦，很好解决：

Fix “Product Flat Data Index process is working now. Please try run this process later.”

To fix this annoying error I got, when I tried to Re-Index the Data all you have to do is

deleting everything in the /var/locks folder

in your magento folder, of course.

That’s it!

有时候你可能需要把相应目录设置为777属性哦。

来源：http://www.psdtomagento.co.uk/category/errors