Why I cannot upload a document to a document library found on another site?

I want to upload a document found in SubsiteA from its parent site. However, this does not work in SP2013, but works fine in Sp2010

I am using the parameters List and Source in my url for Upload form in Sharepoint 2013. But when i try to upload a document, it crashes with exception: Incorrect function.

Here is the url:

http://win-0p1ufik1gie/_layouts/15/Upload.aspx?List={GUID}&Source=http://win-0p1ufik1gie/Test/TestPages/blankPage.aspx

Am i missing a parameter here? And why does this work in sp2010 but not in sp2013?