1. Make sure you have 7gb+as the android need 5gb and twice size of game need to be installed.
2. Try restart your phone before installing. It fix 90 percent of problem here.
3. Make sure the apk you downloaded is not corrupted. Usually, installer will say cannot parsing before giving you option to install it.
4. As last option, you will need to uninstall the game and install the latest version. You need to backup the game saves and replace it after finishing installation.
Here is a guide to find the saves
I suggest wait for Arc reply before doing step 4 as you might mistakenly backup file or something.