Whenever I run the forge installer, I get this error:

java.io.FileNotFoundException: http://files.minecraftforge.net/maven/net/minecraftforge/MercuriusUpdater/1.12/MercuriusUpdater-1.12.jar
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1872)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)
        at net.minecraftforge.installer.DownloadUtils$URLISSupplier.getInput(DownloadUtils.java:457)
        at net.minecraftforge.installer.DownloadUtils$URLISSupplier.getInput(DownloadUtils.java:445)
        at com.google.common.io.ByteStreams$6.openStream(ByteStreams.java:989)
        at com.google.common.io.ByteSource.copyTo(ByteSource.java:202)
        at com.google.common.io.Files.copy(Files.java:382)
        at net.minecraftforge.installer.DownloadUtils.downloadFile(DownloadUtils.java:375)
        at net.minecraftforge.installer.DownloadUtils.downloadInstalledLibraries(DownloadUtils.java:67)
        at net.minecraftforge.installer.ClientInstall.run(ClientInstall.java:131)
        at net.minecraftforge.installer.InstallerAction.run(InstallerAction.java:43)
        at net.minecraftforge.installer.InstallerPanel.run(InstallerPanel.java:406)
        at net.minecraftforge.installer.SimpleInstaller.launchGui(SimpleInstaller.java:165)
        at net.minecraftforge.installer.SimpleInstaller.main(SimpleInstaller.java:51)
File not found in installer archive: /maven/net/minecraftforge/MercuriusUpdater/1.12/MercuriusUpdater-1.12.jar

Tried running as admin, allowed through windows firewall, running as both a jar and as an exe.

Any help?

Bugs are to be expected during game play, but to have a bug in the installer? Come on.

I have the same problem. I can't get it installed. I'll give it a couple of days. 

Tamas just updated Mercurious so this should be resolved.

Im going to push a ASM library fix in a few mins.

 

Edit: Oh wait its the updater, ya he hasn't done that yet. He'll do that in a few mins.