The sdk platform-tools (23.1) is too old to check APIs compiled with API 24; please update

I am getting this error on the latest version of Android Studio and while I have installed both Android SDK Platform API 24 Revision 1 and Android SDK Build-Tools 24.

I have also tried File>Invalidate Caches/ Restart... and Build>Rebuild Project.

EDIT: I have also followed all instructions under Android Developers, but I still get this error.

Thanks in advance for any answers.