Facebook中的验证循环

Question

我是开发Facebook App的新手，我刚刚在Facebook上看到了一个教程并开始开发App。一切都很好，但是当我单击App时，App进入了身份验证的无限循环，并且网址不断增加auth部分。我看过100篇有关开发Facebook应用程序的教程，但它们都陷入了无限循环。可能是什么原因？有人让我知道。有人把它称为``死亡白屏''

Answer 1

When user comes to your canvas, then you look for the signed_request including access token otherwise you redirect to authorization page, then use grants authorization it come backs to your canvas, here:
somehow you can't get the access token, the loop starts.