I finally found out why my app crashes built for release. ProGuard was indeed stripping code from my application but i prevented this by manually adding the classes with the
fixed:
-keep class com.facebook.** {
*;
}
instead of:
-keepattributes Signature
-keep class com.facebook.android.*
-keep class android.webkit.WebViewClient
-keep class * extends android.webkit.WebViewClient
-keepclassmembers class * extends android.webkit.WebViewClient {
;
}
Also be sure to check your hash key in your facebook app settings.