Reminder:
Please do not overwrite APK, or else -hanged- / white/black screen / "Unfortunately client has stopped" will appear.
Un/Reinstall everything, then input your transfer ID/PW to play.
It's knowable to ALWAYS set your transfer ID/PW before maintenance starts or else you have to email their staffs for a resend of PW.
For anybody who worried about having to email the dev because you couldn't install newer APK over this modded one. I recommend using 'ZipSigner' app. IT will change the signed key to generic one which will allow you to install the game over the modded one. Either by using the APK from other mod or clean APK file.
This will allow you to update the game without having to uninstall the game. At least you should be able to access the game to setup the Data Transfer.