Commander feature for tablets has been removed on August 11th, and that's why you're getting this message. Here is the official statement by Vincent0K, from 3 months ago:
You’ve commanded the Battlefield from your sofa, the bus and sometimes in the most awkward of places with the Commander app for Battlefield 4. It’s been a fun ride watching and playing with you all from a bird’s eye view, adding team support wherever possible. But, the time has come and we have to inform you that on August 11th 2015, we will no longer continue our support of the Battlefield 4 Commander app on the iOS and Android platforms.
This is not an easy choice, but we believe the time is right to retire the mobile app as we’re seeing more of our Commanders playing on PC and console. This change means that you’ll no longer be able to download the app from Apple Store or Google Play starting today, April 28th. However, if you have the app downloaded already, you can continue to play it on mobile devices until August 11th. Additionally, this change does not affect in any way the in-game Commander mode experience. You will still be able to take the command and lead your team to victory on your PC and consoles!
We are committed to continuing the support of Battlefield 4 and as always, we wanted to say thanks to you, the community, for playing.
