Cannot install security patch 7405 in my site running on magento 1.9.1.1

[Donald20152016]

Hi there, I had problem with SUPEE 7405 with my website: http://1buy.vn - a Magento site 1.9.1.1

It showed: Hunk #1 FAILED at 227. 1 out of 1 hunk FAILED -- saving rejects to file lib/Varien/Io/File.php.rej

What is that? How I can deal with ? Thanks so much in advance.

Donald

[Mukesh Tiwari]

Hi @Donald20152016

Have you applied SUPEE-5994 patch and all other patched released after that before applying the current patch?

[Donald20152016]

Hi Muk_t

I already installed other security patches, friend.

As my friend's suggestion, I upgrade my site: http://1buy.vn from 1.9.1.1 to 1.9.2.2 (by downloading 1.9.2.2 and upload to my site"s root Magento folder)

Reindex and Release cache already. But my site now is still 1.9.1.1 

Don't know what happened 

Thanks so much for your keen help.

Donald