I just managed to corrupt contents of my Eclipse .metadata directory. Starting up with eclipse -clean did not work out. Deleting .metadata and then importing all projects, p
deleting below file helped me solve my eclipse start up issue. Perforce plugin has always troubled me especially when my machine reboots, next time eclipse tries to recover workspace and craps out.
workspace/.metadata/.plugins/org.eclipse.core.resources/.snap
For your reference, Error I was getting: org.eclipse.core.runtime.CoreException: Plug-in com.perforce.team.ui was unable to load class com.perforce.team.ui.UITeamProvider.