I've created my own key to sign my game:
C:\Program Files\Android\Android Studio\jre\bin\keytool.exe" -genkey -v -keystore myapp.keystore -alias myapp -keyalg RSA -validity 999999
I introduced all the information as explained here https://coronalabs.com/blog/2014/08/26/tutorial-understanding-android-app-signing/
Tried to create an Android build with this key (asked for passwords and all of that, so looked cool), and got this:
14:24:49.432 Testing credentials for 'C:\Users\sergi\myapp.keystore': 14:24:50.583 Picked up JAVA_TOOL_OPTIONS: -Duser.language=en 14:24:50.583 jar signed. 14:24:51.665 Excluding specified files from build: 14:24:51.665 excluding: LaunchScreen.storyboardc 14:24:51.665 excluding: Icon.png 14:24:51.665 excluding: Icon-*dpi.png 14:24:51.665 excluding: Images.xcassets 14:25:56.410 BuildID: 5c9390a53f99c 14:25:56.704 WebServices: downloading build 14:26:02.077 Android build failed (1) after 71 seconds
I've tried with different keys and applications, and I'm getting the same problem.
I'm using the latest stable version of Corona (2018.3326)