Fix for people with the error "An anti-cheat module could not be downloaded or installed"

Spent way too long on this so posting in case it helps someone.

Error was: "An anti-cheat module could not be downloaded or installed. Check your internet connection, VPN, proxy or firewall, then try again."

Which is a lie, it was not my network. I have opnsense with unbound + blocklists and spent hours convinced I was blocking something. Nope. The download works fine, it's the install step that dies.

Check

%LOCALAPPDATA%\Wardogs\ElytraLauncher.log

first. If it says the module downloaded and verified and then you see this: InstallModule failed: - RPC error: - Failed to open input file - Access is denied. (os error 5)

then this is your problem too. If your log says something else then ignore all of this.

What's happening: the launcher downloads the module into your temp folder as you, then tells the Elytra service (runs as SYSTEM) to go open it. If SYSTEM has no rights on your temp folder it just can't read the file and you get that useless network error.

Run

icacls "%TEMP%

and compare. A friend's working machine:

NT AUTHORITY\SYSTEM:(I)(OI)(CI)(F) BUILTIN\Administrators:(I)(OI)(CI)(F) PCNAME\User:(I)(OI)(CI)(F)

Mine:

BUILTIN\Administrators:(F) PCNAME\User:(OI)(CI)(F)

No SYSTEM, and no (I) on anything, meaning inheritance was turned off at some point and a custom ACL slapped on. Probably some debloat or "fix your permissions" script I ran years ago and forgot about. Nothing else ever cared because basically no other software makes a SYSTEM service open a file out of your user temp folder.

Fix, admin prompt:

icacls "%TEMP%" /save "%USERPROFILE%\temp-acl-backup.txt"

icacls "%TEMP%" /inheritance:e

First line is a backup so you can undo it with /restore if it goes wrong. Second one turns inheritance back on and SYSTEM shows up again.

Then reboot. I got a crash on launch right after and thought I broke something else, reboot fixed it.

Embark, if you're reading, your launcher literally has the real error in the log and shows people a firewall message instead !!!