Please Note: This is an Untested build. Please try at your own risk.
My last CM-14.1-OFFICIAL-NIGHTLY build for this device was from 2016.12.25. Unfortunately there is no more officiall LineageOS support.
What are the kernel sources? What is the status of the security updates?
Kernel from official LOS, android security patch is latest availiable, i think from September, vendor patch is from latest availiable LOS rom, maybe from 25.12.2016 if you said it was last rom released.
If going unofficial, there is a better, more recent and still actively developped (based on LoS 16 - Pie) and supported ROM:
I use it with Pico Gapps (still waiting for Micro-G…). It’s fast, smooth, responsive. A dream for our 5-year old phones before I get a Fairphone
In case it helps…
I made an update for this device, enjoy :
Don’t forget to backup and share your experience, thanks
I tried your version but I have an error on installation :
E1001 : Failed to update system image Updater process ended with ERROR: 7 Error installing zip file '/external_sd/e-0.9-n-20200706-UNOFFICIAL-h815.zip'
Welcome in the forum
I guess you use the 3.4.0 version of TWRP ?
Some users solved the issue by turning the phone off (TWRP > Reboot > Turn off) and trying again.
If it doesn’t work, use TWRP 3.3.1 instead.
I tried to install the lineageos build ant I had the same error.
I found that I did not root my phone and after rooting it I successfully installed the /e/ image.
No OTA update. But it’s not a big deal at all, just flash the next update (if any).
I’ve been using Lineage 16 (Pie) from steadfasterX on my G4 for a long time and most of the time it worked reallly flawlessly: updates work great (still flashing the old way though - no OTA) but it looks like his e work is even better (OTA updates,…).
Hope he can make it “official” in case it matters. As soon as I find my spare G4,I’ll give it a try.
SteadfasterX (https://forum.xda-developers.com/m/steadfasterx.5545101/) keeps building both LineageOS and /e/ OS for the LG G4 h815 (and others) : https://leech.binbash.rocks:8008/e-os/pie/h815/