
For GT-I8160 - Galaxy Ace 2
Installation :
Boot into recovery *
Install temporary CWM **
Wipe data/cache/dalvik (optional)
Flash MIUI_v5_4.1.2_GT-I8160_X
Install Multi-lang Package (optional)
Flash Themes fix
Reboot
Flash Gapps from recovery
Reboot
Enjoy !

* Vol up + Home + Power
** Skip if you are using custom kernel with CWM built-in
INSTALL GAPPS ONLY AFTER FIRST BOOT!! NO BEFORE!!
If still not working just flash it and wipe cache, factory reset and wipe dalvik cache
Downloads :
MIUI v5 GT-I8160 Beta 3
Beta 3 Multi-lang
Themes fix
Small Gapps
Gapps
MIUI Keyboard
Modified Vold.fstab
Original Vold.fstab