May be your application have an error.
Try to debug your application on emulator or real devices before export to apk
You can use MEmu player or Genymotion to debug. But I prefer MEmu.
When MEmu lauched, i run this command from my woking ionic folder (save it as runMEmu.cmd file to your working project).
cmd /k ionic cordova run android --target 127.0.0.1:21503 --livereload --prop
cmd /k : to keep cmd window after run finished
ionic cordova run android : is ionic CLI command, that run your application on emulator or real devices.
–target 127.0.0.1:21503 : mean the devices you want to run this application is MEmu player
–livereload --prop : is livereload the project when you change files in your folder. --prop mean i dont know
Then you open chrome and type the address:
chrome://inspect/ you will see MEmu and view the console of your application.