Import failed. Please add an icon to your APK.

I made a game using unity for android. I did every thing ok, I built and run the game on my device and it’s working perfectly.BUT when I try to upload the apk file to google play it’s uploading untill it reach 100% and then pop up a message that says :

Import failed.
Please add an icon to your APK.

I dont really know what’s happend cuz I added already an icon to my game in unity (512*512 PNG image), and I already uploaded many apk files of other games to google play without problems.
I deleted my current icon in my unity project and switch off unity, then run it again and added once again the icon and built new apk file. But it’s not working, google play show me the same message.
If someone can help me i will be really thankful.

I am use Admob Unity Plugin, and I had same problem.

I added android:icon="@drawable/app_icon" to Assets/Plugins/Android/AndroidManifest.xml file.

  <application android:icon="@drawable/app_icon">

It’s was help me.

Get rich today and take the risk of transforming your own life.Try and
get an ATM card blank today from (MR ANDERSON) and be among the lucky ones who are benefiting from this card. This ATM card in white set is capable of hacking into any ATM anywhere in the world. I have to know about this ATM card when I was searching for job online about a month ago…It has really changed my life forever and now I can say I’m rich because I am a living testimony. The less money I get in a day with this card is $ 3,000.Every now and then keep pumping money into my is programmed and also has a technique that makes it impossible for the CCTV to detect you…For details on how to get yours today, email