我也面临这个问题。首先我要知道你的Facebook应用程序中输入该密钥散列值，如果它是 ga0RGNYHvNM5d0SLGQfpQWAPGJ8 = ，那么这就是问题所在。我想，您输入

I also faced this problem. First of all I need to know which Key Hash value you entered on facebook app if it is 'ga0RGNYHvNM5d0SLGQfpQWAPGJ8=' then that is the problem. I think you entered

密钥工具-exportcert -alias androiddebugkey -keystore   〜/ .android / debug.keystore | OpenSSL的SHA1 -binary | OpenSSL的BASE64

keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore | openssl sha1 -binary | openssl base64

这一个终端上输入你自己的密码生成密钥的哈希值。如果你这样做了，请试着做下面的事情也输入端子上面的命令（我使用Ubuntu（Linux）的。你输入相应的命令，它使用的是OS）和输入密码为机器人 。这个时候你会得到一个不同的哎哈希值。复制的值，并将其保存为您的Facebook应用程序的关键哈希值。之后，检查它是否工作。对我来说，它的工作。这将当我们使用调试键发生。做完这一切，当你即将发布Android市场上这个程序，你必须根据你所使用的私钥再次更改密钥散列值。试试这可能是这会帮助你。

this one on the terminal and you entered your own password to generate the key hash. if you done that please try do the following things also you enter the above command on terminal(I am using UBUNTU(linux). You type the command corresponding to which OS you are using) and enter the password as 'android'. This time you will get a different hey hash value. Copy that value and save it as the key hash value for your facebook app. After that check it is working or not. For me it worked. This will occur when we are using the debug key. After all this when you are about to publish this application on the Android market you will have to again change the key hash value according to the private key you are using. Try this may be this will help you.