This is the proven method for MIUI V4 ROM and CyanogenMod 10.2 (Jelly Bean 4.3.1)
1. Download the MIUI V4 ROM file, GApps for MIUI and Xperia keyboard from XDA forums over here for S3 Mini.
or Download the Cyanogenmod 10.2 files, and GApps from Maclaw over here.
2. Copy into external Sdcard.
3. Shut down device. Enter recovery mode by holding the volume up, home button and power button simultaneously.
4. I used TeamWin's TWRP. Then follow these steps:
- Full wipe (dalvik, cache and data)
- Flash the ROM
- Flash the GApps (check that they are for the correct Android version!)
For MIUI V4 ROM only:
- Flash the Xperia Keyboard (necessary for MIUI V4 ROM because the MIUI keyboard is 'force-closing' (but you can install other keyboards later).
Common Whatsapp issues and fixes:
(1) Whatsapp Contact List is missing
This is usually due to a Security app on the custom ROM that is denying Whatsapp permission to access your Contact Book. Under MIUI V4 Rom, go into the LBE Guard app to allow Whatsapp access.
(2) Whatsapp unable to send and receive under mobile data connection (but ok when connected to Wifi).
This is due to the phone having the wrong APN setting. Under M1, this was resolved by choosing the Sunsurf Internet APN. This should already been detected. If not, they are:
Name: Sunsurf Internet
Proxy: Not set
Port: Not set
username: Not set
password: Not set
server: not set
MMSC: not set
MMS proxy: not set
MMS protocol: WAP 2.0
authentication type: not set
APN type: default, hipri