Sorry I think I’m annoying, but yesterday my phone was again unusable (i.e. no network at all) from changing platform.xml on running system with Amaze editor although correcting read permissions afterwards. Fortunately this time I have a two days old backup on 16.06 version.
I don’t know for what reason this happens but I have to warn about changing platform.xml on running system. There could be a remaining risk to make your phone unusable (maybe other running apps writing to remounted /system).
I recommend to start in TWRP recovery mode and copy a changed version of platform.xml
(for example prepared on ExtSDCard using Amaze editor) into /system/etc/permissions.
I had done this immediately after installing the update zip file for 16.07 and all is ok so far.
I will add my recommendation to ✏ Update Guide for a modified FP Open OS (with Gapps, Xposed and more)