and if so do i need the downgrade mod from nexus to play ?

Yes it works fine with the Steam version

No you do not "Need" the downgrader it is supposed to make it easier to downgrade so if you are happy to use the downgrader you can

OR

you can use the steam console, Excellent (pinned) guide at the nexus in the fallout 4 forum

has all the relevant codes to paste into the steam console for version .163 which is the version you want for Folon

just do one at a time or your might find it takes a very long time to download

this was the way I installed

downloaded .163 through the console

ran fallout 4 to get my ini files set up & make sure is all running correctly then set the app manifest for FO4 to read only so steam does not update it.

Then I installed using the offline installer, though by that stage you should be able to just install from your gog page for Folon if you wish :-)

I am sure it worked when you did the installation, but now it doesn't seem to work anymore:

download_depot 377160 377163 5819088023757897745
Depot download failed : error downloading manifest 5819088023757897745 from fastly.cdn.steampipe.steamcontent.com (Access Denied)

I own the game and all 6 DLCs.

Hi again jgamer79

some things to try if you haven't already tried them, sorry if they sound basic

restart your router! basic but sometimes is all it takes lol

are you running steam as admin? if not exit steam & try again as admin

is steam in program files on c:/drive? if so move to something like c:/steam as being in program files can cause issues especially when modding

guide to move steam if needed https://help.steampowered.com/en/faqs/view/4BD4-4528-6B2E-8327 read thouroughly first

try clearing download cache in steam setting

disable steam cloud (you'll need to do this for folon anyway)

under storage click the elipses (three dots) and click repair library

reboot your pc

Just to note as it said "access denied" you do need to be logged in to your steam account

it could also just be steam having issues being a holiday (very busy time)

fallout london also have the exact same instructions on their site with a different layout (found it just after posting last time lol.)

here is the link https://fallout4london.com/release/

one final thought though it shouldn't make any difference did you type it in or did you copy paste(ctrl v)?
try copy pasting if you typed it into the console as I said shouldn't make any difference but I've known weirder things with browsers!!

sorry for the delay in replying have been trying it again myself though had a couple of issues myself so it could well be steam. picking the wrong one didn't help me & my internet is averaging 1MB atm lol.

Ok so I had an issue downloading 377160/161 connection timed out,

though the 377160 377163 downloaded fine first time even if was painfully slow lol which "could" have just been my internet!?

Hth

edited to try & fix underlining

Did you uninstall FO4 first? I did that & I don't think I could download from the depot.

IIRC I re-installed zipped the data folder then deleted the contents of Data then downloaded