BungeeCord Main Thread Error

I'm getting this "SEVERE Exception in thread "main"" Error.
My console reads:

23.08 17:56:16 [Server] SEVERE at net.md_5.bungee.Bootstrap.main(Bootstrap.java:65)
23.08 17:56:16 [Server] SEVERE at net.md_5.bungee.BungeeCord.start(BungeeCord.java:228)
23.08 17:56:16 [Server] SEVERE at net.md_5.bungee.conf.Configuration.load(Configuration.java:112)
23.08 17:56:16 [Server] SEVERE at com.google.common.base.Preconditions.checkArgument(Preconditions.java:148)
23.08 17:56:16 [Server] SEVERE...

BungeeCord Main Thread Error