For phrasing problem there are few things you can try.
1.open from browser download tab (if you downloaded on telephone), it might sound stupid but more than few times I managed to install game just from there when file browser gave me error.
2.Try opening with different file manager and it just may work.
3.Redownload and try first steps again
For App not installed there are also few issues
1. Check if you have enough free space (for me it was about 4.5-7GB, yes you actually need that much to install game sometimes)
2.Download is corrupted, so redownload.
3.Your smartphone/tablet just can't install it, and it is compatibility problem. Nothing you can do about it.