master reset on k850i help

Im planing to do master reset on k850i R1Fa035 because im delete something in tpa/system, but im forgot to do back-up on begain of tuning my phone.. now i cant in on file menager, or entertainament..
so im wondering if i do master reset, did will be all default in tpa/system ...? pls help me

Master Reset cann't help you, must flash phone with A2uploader (Main, FS and CDA) or update via SEUS (if is available).

You can find extracted filesystems on the internet, donwload k850 extracted filesystem and upload the files that you need :a013