*** YOU NEED TO REGISTER ON THE FORUM BEFORE YOU CAN ACCESS THE DOWNLOAD LINK ***
INSTALLATION INSTRUCTIONS
http://www.xperiablog.net/2015/03/17/guide-to-installing-xperia-lollipop-using-xperifirm-and-flashtool/
- Open link above and skip to the section entitled “FlashTool steps”.
- As you have already downloaded the FTF firmware file, skip to the section where you need to “Flash device”.
XPERIA FIRMWARE DETAILS
This is official stock Sony Xperia firmware.
Model: Sony Xperia M2 (D2303)
Firmware version: 18.3.1.C.1.16_R1B
Region: Central Europe 1 (Generic) [1281-1548]
Android version: 4.4.4

Xperia M2_D2303_18.3.1.C.1.16_Central Europe 1_Generic 4.4.4
Sony Xperia M2 (D2303) Android 4.4.4 firmware - Generic Central Europe 1