Error is at step 9.
This is the process I went through:
Fresh download of minecraft from minecraft.net ["Download for Windows"].
Installed minecraft.
Launched the Minecraft Launcher and went to "Launch Options" and "Add new", set version to 1.12.2. Saved.
Opened that version "Play 1.12.2".
Closed the game and launcher.
Went to https://files.minecraftforge.net/ and downloaded the "Windows Installer" for ver 14.23.4.2747
Opened the installer and left it on the default "Install client". Install was successful (see attached "installer.log" attachment 1).
Opened the Minecraft Launcher and selected the "with forge"
Got this error: https://i.imgur.com/a2axCJu.png
Note: when I go to the URL in the error (), I get a HTTP 404 on my browser as well.
At this point I figured, maybe I have the wrong installer? So I go and delete my .minecraft folder in %appdata%
Repeated steps 3. - 5. from above.
Download "Installer" from https://files.minecraftforge.net/ (same ver 14.23.4.2747)
Repeated step 7. & step 8. [attached "installer.log" attachment 2]
Got this error: https://i.imgur.com/H1nXZTz.png
Maybe wrong installer again? So I go and delete my .minecraft folder in %appdata%
Repeated steps 3. - 5. from above.
Attempt to download "Universal" from https://files.minecraftforge.net/ (same ver 14.23.4.2747)
File reaches the 4.7MB/4.7 MB
I get the "This type of file can harm your computer. Do you want to keep forge....jar anyway?" I click "Keep"
I get a "Failed - Download Error" from my browser
I switch browsers (tried Chrome, then Edge, then Firefox), all similar download fails.
I tried flushing my DNS in command prompt "ipconfig" & tried using my VPN with the different browsers, no luck.
I tried disconnecting my ethernet and using my 4G on my phone via tethering with the different browsers, no luck.
Also, tracert in command prompt to 158.69.55.219 [cerberus.minecraftforge.net] completes with no issues [may be useful information, I am not sure].
Please let me know if I am doing something wrong or missing a step.
installer.log
installer.log