Can't reboot system after CyanogenMod 14.1 update
Thanks a lot esQmo for your answer!

I finally managed to return to stock. To do so:


I downloaded LGUP here: http://oceanhost.eu/eps4h4pmwphu/LGUP.zip.htm and I installed LGUP_8994_DLL_Ver_0_0_3_23 first and then LGUP_Install_Ver_1_14_3 (I am running Windows 10)
I downloaded the Frenche version of Marshmallow 6.0 for my LG G4 h815 here: http://storagecow.eu/index.php?dir=Xda%2FLG+G4%2FH815%2FMarshmallow+6.0%2F
Downloaded the LG drivers
I restart my phone into Download Mode and I plugged it to my computer:


4.1. Power Down the LG G4

4.2. Press and Hold the Volume Up Button on the LG G4

4.3. While Holding Volume Up, Plug the USB Cable into the LG G4

4.4. Continue Holding the Volume Up Button After You See ‘Download Mode’

4.5. Let Go of the Volume Up Button When You See the ‘Firmware Update’ Screen on the LG G4


I runned LGUP and I refurbished my phone with the .kdz firmware file downloaded in 2.


N.B.: if your computer does not detect your mobile device, you should change the port to have COM41

Good luck!