Same Error here, Problem persists after reinstallation (.minecraft folder cleared / redownloaded).
I also tested some versions between 1334 and 1404.
From 1334 until (i think) 1361 another error occured, which was fixed, according to the bug report.
Client> Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/logging/log4j/Level ...
A fix would be great. For me, no forge = no 1.8 ;(