I'm trying to wrap my head around why this magento patch keeps failing. Unfortunately due to the significance, I cant just ignore the patch as it's a serious security issue.

Essentially, I've run the patch PATCH_SUPEE-7405_CE_1.9.1.1_v1-2016-01-20-04-42-03.sh on my server and it keeps failing at

patching file lib/Varien/Io/File.php
Hunk #1 FAILED at 227.

My full output of the bash command

Checking if patch can be applied/reverted successfully...
ERROR: Patch can't be applied/reverted successfully.

patching file app/code/core/Mage/Admin/Model/Observer.php
patching file app/code/core/Mage/Admin/Model/Redirectpolicy.php
patching file app/code/core/Mage/Admin/Model/Resource/User.php
patching file app/code/core/Mage/Admin/Model/User.php
patching file app/code/core/Mage/Adminhtml/Block/Sales/Order/View/Tab/History.php
patching file app/code/core/Mage/Adminhtml/Block/Widget/Grid.php
patching file app/code/core/Mage/Adminhtml/Helper/Catalog/Product/Edit/Action/Attribute.php
patching file app/code/core/Mage/Adminhtml/Helper/Sales.php
patching file app/code/core/Mage/Adminhtml/Model/System/Config/Backend/File.php
patching file app/code/core/Mage/Adminhtml/Model/System/Config/Backend/Image.php
patching file app/code/core/Mage/Adminhtml/Model/System/Config/Backend/Image/Favicon.php
patching file app/code/core/Mage/Adminhtml/controllers/IndexController.php
patching file app/code/core/Mage/Authorizenet/Helper/Admin.php
patching file app/code/core/Mage/Authorizenet/Helper/Data.php
patching file app/code/core/Mage/Authorizenet/controllers/Adminhtml/Authorizenet/Directpost/PaymentController.php
patching file app/code/core/Mage/Captcha/etc/config.xml
patching file app/code/core/Mage/Catalog/Block/Product/View/Options/Type/Select.php
patching file app/code/core/Mage/Catalog/Model/Category/Attribute/Backend/Image.php
patching file app/code/core/Mage/Catalog/Model/Resource/Product/Attribute/Backend/Image.php
patching file app/code/core/Mage/CatalogIndex/etc/config.xml
patching file app/code/core/Mage/CatalogInventory/Helper/Minsaleqty.php
patching file app/code/core/Mage/Checkout/Block/Cart/Item/Renderer.php
patching file app/code/core/Mage/Checkout/controllers/CartController.php
patching file app/code/core/Mage/Checkout/controllers/OnepageController.php
Hunk #1 FAILED at 102.
1 out of 1 hunk FAILED -- saving rejects to file app/code/core/Mage/Checkout/controllers/OnepageController.php.rej
patching file app/code/core/Mage/Core/Helper/Data.php
patching file app/code/core/Mage/Core/Model/App.php
patching file app/code/core/Mage/Core/Model/Config.php
patching file app/code/core/Mage/Core/Model/Email/Queue.php
patching file app/code/core/Mage/Core/Model/Email/Template/Filter.php
Hunk #1 FAILED at 171.
Hunk #2 succeeded at 182 (offset -10 lines).
1 out of 2 hunks FAILED -- saving rejects to file app/code/core/Mage/Core/Model/Email/Template/Filter.php.rej
patching file app/code/core/Mage/Core/Model/File/Validator/Image.php
patching file app/code/core/Mage/Core/Model/Input/Filter/MaliciousCode.php
patching file app/code/core/Mage/Core/Model/Session.php
patching file app/code/core/Mage/Customer/controllers/AccountController.php
Hunk #1 succeeded at 65 (offset -3 lines).
patching file app/code/core/Mage/Dataflow/Model/Convert/Parser/Csv.php
Hunk #2 FAILED at 264.
1 out of 2 hunks FAILED -- saving rejects to file app/code/core/Mage/Dataflow/Model/Convert/Parser/Csv.php.rej
patching file app/code/core/Mage/Downloadable/controllers/CustomerController.php
patching file app/code/core/Mage/ImportExport/Model/Export/Adapter/Abstract.php
patching file app/code/core/Mage/ImportExport/Model/Export/Adapter/Csv.php
Hunk #2 FAILED at 118.
Hunk #3 succeeded at 121 (offset -12 lines).
1 out of 3 hunks FAILED -- saving rejects to file app/code/core/Mage/ImportExport/Model/Export/Adapter/Csv.php.rej
patching file app/code/core/Mage/ImportExport/Model/Import/Entity/Abstract.php
patching file app/code/core/Mage/ImportExport/etc/config.xml
patching file app/code/core/Mage/ImportExport/etc/system.xml
patching file app/code/core/Mage/Newsletter/Model/Observer.php
patching file app/code/core/Mage/Newsletter/Model/Queue.php
patching file app/code/core/Mage/Page/etc/system.xml
patching file app/code/core/Mage/Paypal/controllers/PayflowController.php
patching file app/code/core/Mage/Paypal/controllers/PayflowadvancedController.php
patching file app/code/core/Mage/Paypal/etc/config.xml
patching file app/code/core/Mage/Persistent/etc/config.xml
patching file app/code/core/Mage/Review/controllers/ProductController.php
patching file app/code/core/Mage/Rss/Block/Catalog/Salesrule.php
patching file app/code/core/Mage/Rss/Helper/Order.php
patching file app/code/core/Mage/Sales/Helper/Guest.php
patching file app/code/core/Mage/Sales/Model/Quote/Address.php
patching file app/code/core/Mage/Sales/Model/Quote/Item.php
patching file app/code/core/Zend/Xml/Security.php
patching file app/design/adminhtml/default/default/template/authorizenet/directpost/iframe.phtml
patching file app/design/adminhtml/default/default/template/bundle/sales/creditmemo/create/items/renderer.phtml
patching file app/design/adminhtml/default/default/template/bundle/sales/creditmemo/view/items/renderer.phtml
patching file app/design/adminhtml/default/default/template/bundle/sales/invoice/create/items/renderer.phtml
patching file app/design/adminhtml/default/default/template/bundle/sales/invoice/view/items/renderer.phtml
patching file app/design/adminhtml/default/default/template/bundle/sales/order/view/items/renderer.phtml
patching file app/design/adminhtml/default/default/template/bundle/sales/shipment/create/items/renderer.phtml
patching file app/design/adminhtml/default/default/template/bundle/sales/shipment/view/items/renderer.phtml
patching file app/design/adminhtml/default/default/template/catalog/product/composite/fieldset/options/type/file.phtml
patching file app/design/adminhtml/default/default/template/downloadable/sales/items/column/downloadable/creditmemo/name.phtml
patching file app/design/adminhtml/default/default/template/downloadable/sales/items/column/downloadable/invoice/name.phtml
patching file app/design/adminhtml/default/default/template/downloadable/sales/items/column/downloadable/name.phtml
patching file app/design/adminhtml/default/default/template/sales/items/column/name.phtml
patching file app/design/adminhtml/default/default/template/sales/items/renderer/default.phtml
patching file app/design/adminhtml/default/default/template/sales/order/totals/discount.phtml
patching file app/design/adminhtml/default/default/template/sales/order/view/info.phtml
patching file app/design/frontend/base/default/template/catalog/product/view/options/type/file.phtml
patching file app/design/frontend/base/default/template/rss/order/details.phtml
patching file lib/Varien/File/Uploader.php
patching file lib/Varien/Io/File.php
Hunk #1 FAILED at 227.
1 out of 1 hunk FAILED -- saving rejects to file lib/Varien/Io/File.php.rej

Note: There is no such file lib/Varien/Io/File.php.rej

What I have tried:

1. I have tried the advice of trying to install prior patches e.g. patch PATCH_SUPEE-5994_CE_1.6.0.0_v1-2015-05-15-04-34-46 onwards as suggested in other topics and I seem to get errors with this as well

   Checking if patch can be applied/reverted successfully...
   ERROR: Patch can't be applied/reverted successfully.
   
   patching file app/code/core/Mage/Authorizenet/controllers/Directpost/PaymentController.php
   patching file app/code/core/Mage/Core/Controller/Varien/Router/Admin.php
   patching file app/code/core/Mage/Core/Controller/Varien/Router/Standard.php
   patching file app/code/core/Mage/Customer/Model/Customer.php
   patching file app/code/core/Mage/Dataflow/Model/Convert/Parser/Csv.php
   patching file app/code/core/Mage/ImportExport/Model/Export/Adapter/Csv.php
   patching file app/code/core/Mage/Install/Controller/Router/Install.php
   patching file app/code/core/Mage/Install/etc/config.xml
   patching file app/code/core/Mage/Sales/controllers/Recurring/ProfileController.php
   patching file downloader/Maged/Model/Connect.php
   Reversed (or previously applied) patch detected!  Assume -R? [n]
   Apply anyway? [n]
   Skipping patch.
   1 out of 1 hunk ignored -- saving rejects to file downloader/Maged/Model/Connect.php.rej
   patching file downloader/Maged/View.php
   Reversed (or previously applied) patch detected!  Assume -R? [n]
   Apply anyway? [n]
   Skipping patch.
   1 out of 1 hunk ignored -- saving rejects to file downloader/Maged/View.php.rej
   patching file downloader/template/connect/packages_prepare.phtml
   Hunk #1 FAILED at 33.
   1 out of 1 hunk FAILED -- saving rejects to file downloader/template/connect/packages_prepare.phtml.rej
   patching file downloader/template/messages.phtml
   Reversed (or previously applied) patch detected!  Assume -R? [n]
   Apply anyway? [n]
   Skipping patch.
   1 out of 1 hunk ignored -- saving rejects to file downloader/template/messages.phtml.rej
   patching file get.php
   Hunk #1 succeeded at 36 (offset -1 lines).
   patching file lib/PEAR/PEAR/PEAR.php
   patching file lib/PEAR/PEAR/PEAR5.php
   patching file lib/Varien/Io/File.php
   

2. Pretty much trying to apply every other patch and the only one that does install is SUPEE-6482, probably because previous ones are not installed.

3. Staring at my screen hoping that the problem would magically fix itself.

4. Crying in the corner

I was considering following a tutorial where files could just be replaced, however seeing as the automated patcher doesn't work, I see that as being a slightly bad idea.

Any help would be greatly appreciated!