this is the log that came up on my desktop, i'm using the forge-1.7.10-10.13.4.1448-1.7.10-installer and i've updated my java to java 8.
Exception in thread "main" java.lang.ExceptionInInitializerError
at net.minecraftforge.installer.ClientInstall.getSponsorMessage(ClientInstall.java:326)
at net.minecraftforge.installer.InstallerAction.getSponsorMessage(InstallerAction.java:59)
at net.minecraftforge.installer.InstallerPanel.updateFilePath(InstallerPanel.java:236)
at net.minecraftforge.installer.InstallerPanel.<init>(InstallerPanel.java:217)
at net.minecraftforge.installer.SimpleInstaller.launchGui(SimpleInstaller.java:153)
at net.minecraftforge.installer.SimpleInstaller.main(SimpleInstaller.java:40)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 2
at net.minecraftforge.installer.MirrorData.buildMirrorList(MirrorData.java:84)
at net.minecraftforge.installer.MirrorData.<init>(MirrorData.java:63)
at net.minecraftforge.installer.MirrorData.<clinit>(MirrorData.java:17)
... 6 more