Hi atharstar,
i made a correction after my first post about proguard:
check this line: @android.webkit.JavascriptInterface <methods>;
# For communication with AdColony's WebView
-keepclassmembers class * {
@android.webkit.JavascriptInterface <methods>;
}
# For removing warnings due to lack of Multi-Window support
-dontwarn android.app.Activity
Moreover i haven’t tested the plugins with 4.12, mainly with 4.13-4.14 versions.
But first check again the proguard additions with the correct format.