Jar mismatch! Fix your dependencies for the FacebookSDK

Question

Try to remove the android-support-v4.jar file from the libs folder of your project.

Good Luck.

If there is any JAR file with same name in the libs folder of the Library and your Project, they must have the same size(same jar files).

If now just replace one of them with the other

The Android FacebookSDK includes its own version of android-support-v4.jar, and it's most likely the conflicting jar.

Open project preferences, select Java Build Path and remove android-support-v4.jar from the root, and things should compile well again.