[Sony Xperia ZR] DoO37:
First You need to edit the META-INF\com\google\android\ "updater-script" file with any text editor (i suggest Notepad++)

and replace the line

[COLOR="Red"]mount("yaffs2", "MTD", "system", "/system");[/COLOR]

with

[COLOR="Lime"]mount("ext4", "EMMC", "/dev/block/platform/msm_sdcc.1/by-name/system", "/system");[/COLOR]

Second you should set the right permissions for the file (as for me i don't know what is the right one for system/etc ,i would use the whole "set permission" script from Sijav flashable zip ,it will work anyway

set_perm_recursive(0, 0, 0755, 0644, "/system");
set_perm_recursive(0, 0, 0755, 0755, "/system/etc/init.d");
set_perm_recursive(0, 2000, 0755, 0755, "/system/bin");
set_perm(0, 3003, 06755, "/system/bin/ip");
set_perm(0, 3003, 02750, "/system/bin/netcfg");
set_perm(0, 3004, 02755, "/system/bin/ping");
set_perm(0, 2000, 06750, "/system/bin/run-as");
set_perm_recursive(1002, 1002, 0755, 0440, "/system/etc/bluetooth");
set_perm(0, 0, 0755, "/system/etc/bluetooth");
set_perm(1000, 1000, 0640, "/system/etc/bluetooth/auto_pair_devlist.conf");
set_perm(3002, 3002, 0444, "/system/etc/bluetooth/blacklist.conf");
set_perm(1002, 1002, 0440, "/system/etc/bluetooth/main.conf");
set_perm(1002, 1000, 0640, "/system/etc/bluetooth/auto_pairing.conf");
set_perm(1002, 1002, 0440, "/system/etc/bluetooth/audio.conf");
set_perm(3002, 3002, 0444, "/system/etc/bluetooth/bt_did.conf");
set_perm(3002, 3002, 0444, "/system/etc/bluetooth/bt_stack.conf");
set_perm(1014, 2000, 0550, "/system/etc/dhcpcd/dhcpcd-run-hooks");
set_perm(0, 0, 0755, "/system/etc/install-recovery.sh");
set_perm(0, 0, 0755, "/system/etc/init.d/99SuperSUDaemon");
set_perm(0, 0, 0755, "/system/etc/init.d");
set_perm_recursive(0, 2000, 0755, 0644, "/system/etc/firmware/wlan");
set_perm(0, 0, 0644, "/system/etc/firmware/wlan/prima/WCNSS_cfg.dat");
set_perm_recursive(0, 0, 0755, 0555, "/system/etc/ppp");
set_perm(0, 2000, 0755, "/system/vendor");
set_perm(0, 2000, 0755, "/system/vendor/camera");
set_perm_recursive(0, 2000, 0755, 0644, "/system/vendor/etc");
set_perm(0, 0, 0644, "/system/vendor/etc/audio_effects.conf");
set_perm(0, 2000, 0755, "/system/vendor/lib");
set_perm(0, 2000, 0755, "/system/vendor/lib/hw");
set_perm(0, 0, 0644, "/system/vendor/lib/libwvdrm_L3.so");
set_perm(0, 0, 0644, "/system/vendor/lib/libwvm.so");
set_perm(0, 0, 0644, "/system/vendor/lib/libWVStreamControlAPI_L3.so");
set_perm_recursive(0, 2000, 0755, 0644, "/system/vendor/lib/drm");
set_perm(0, 0, 0644, "/system/vendor/lib/drm/libdrmwvmplugin.so");
set_perm(0, 2000, 0755, "/system/vendor/firmware");
set_perm(0, 0, 0644, "/system/vendor/firmware/libpn544_fw_c2.so");
set_perm(0, 0, 0644, "/system/vendor/firmware/libpn544_fw_c3.so");
set_perm(0, 0, 0644, "/system/build.prop");
set_perm_recursive(0, 2000, 0755, 0755, "/system/xbin");
set_perm(0, 0, 06755, "/system/bin/su");
set_perm(0, 1000, 0755, "/system/xbin/busybox");
set_perm(0, 0, 0755, "/system/bin/ctrlaltdel");

Third your flashable zip only contains "etc" folder in root ,while it should be in system/etc

Anyway i made it for you ,haven't test it but it should work ,you may try flashing it and don't forget to take backup before flashing :)