Unable to resolve superclass android.support.v4.app.FragmentActivity

Problem:

When trying to implement an Android app using the Facebook SDK (v3.18) I get an error similar to: Unable to resolve superclass of Lcom/facebook/samples/hellofacebook/HelloFacebookSampleActivity;

In the above example, HelloFacebookSampleActivity is a subclass of android.support.v4.app.FragmentActivity.

I have already added the android-support-v4.jar to my project (found in FacebookSDK/libs) and Eclipse ADT does not show any linker errors. However, whenever the app is compiled and run on a device it crashes immediately and gives the above error in the log.

Solution:

Try the following:

• Right click on your project in Eclipse
• Select: Build Path -> Configure Build Path
• Select the "Order and Export" tab
• Make sure that "android-support-v4.jar" is checked

When you try and run the project now, the app should hopefully be able to find the linked FragmentActivity from the now-included android-support-v4.jar.

References:

• http://stackoverflow.com/questions/16663686/link-of-class-landroid-support-v4-app-watson-failed-unable-to-resolve-superc?answertab=votes#tab-top