android manifest merger failed, gms play services / firebase

Question

I am trying to add firebase to my app using the firebaseUI. As the documentations says, I have used the corresponding gms:play-services (11.0.4) with the firebaseUI version

Answer 1

It's happening because two versions of support libraries are clashing. On top, you have declared

buildToolsVersion "26.0.1"

and in dependencies, the version is 26.0.0

compile 'com.android.support:design:26.0.0'

Just change the support library version to 26.0.1 and it will work fine. I did the same, worked flawlessly in my case.