Last minute change from Facebook (on Dec 10, 2012). Facebook have removed Application Profile page which is created by default when you start a new application – therefore you are no longer to add Facebook application to Facebook page with previous instructions
Today, we are announcing that we will remove all App Profile Pages on February 1st, 2012. Though similar in appearance, the automatically generated App Profile Pages differ in features from traditional Facebook Pages, and over time the inconsistencies between the two, such as different Insights, APIs, and distribution channels, have become more apparent.
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In order to add Facebook Application to your Facebook page, follow this post
You also can find more information on this issue here
The simplest way is access the direct URL for add page end point
Hope this helps.
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