You'd better conduct factory reset and wipe cache partition first . Back up your phone before factory reset. If there are some errors during flashing, you can flash official rom first and then try again.

ROM download link: https://mega.co.nz/#!J5hEEAjQ!NLwSjM...Etjsqka05GgsRs

ROM flashing tutorial:
http://bbs.elephone.hk/thread-1037-1...l#.VUnF2vRAWk4

Changelog:
fix- GSM (0515)
fix- the format of the video (0515)
update- destop icons (0515)
adjust- some parameter of system (0515)
improve-fluency of system (0515)
fIX- boot problem after flash (0518)

There are nearly 90 different kinds of language in this phone, you can change to any kind language you prefer.