I am learning how to use Ionic by doing a test application but I have had this problem for two days. I have looked for possible solutions but none has worked for me.
This is due to compat plugin. Remove that plugin if you have older version (less than 1.2.0) and set cordova-android@6.3.0
cordova plugin rm cordova-plugin-compat --force
cordova plugin add cordova-plugin-compat@1.2.0
cordova platform rm android
ionic cordova platform add android@6.3.0
Working at my case. Thanks :)