DistributionSigning settings are not all set. Check the DistributionSettings UE4

The solution depends on what’s your intention about the game: shipping it for distribution or it was unintentional the abilitation of that setting?

1. If you don’t want to Ship For Distribution, uncheck the setting in Packaging page of settings.

   
   Uncheck the “For Distribution” field in the Packaging section of Project Settings if it wasn’t your intention to ship the game For Distribution. This isn’t advised this is your release build!

2. If it was your intention, create a keystore.

   It is more oddly that you were instead trying to actually package the project for distribution but you just failed because you didn’t know you need a Keystore in order to do that. How to create a Keystore? It’s easy, and you don’t even need external tools. Just follow this guide!

3. Add the keystore in \Build\Android path of your project

   If you don’t know how to reach that path, just right click with the mouse a random object in Content Browser, click on Show in Explorer, go back to the main folder then open the folder “Build” and then the folder “Android”. You should put the Keystore there!

4. Let Unreal Engine 4 know the information inside the Keystore

   Obviously to sign your game with packaging, Unreal Engine 4 must know the information you put inside the Keystore because the Keystore itself is encrypted and can’t be read directly by the engine. In order to do this, open the project settings page.
   Scroll down till to “Distribution Signing” section. Compile the four empty fields (you may want to leave Key Password blank if you are already compiling the above field).
   This was the main problem that caused the Distribution Signed to not be all set.

5. Rebuild the game!

   Now that you’ve followed all passages, just rebuild your game! Select the Android target you prefer, and the error won’t appear anymore.