Losing customized Keymap on startup

I have on several occasions lost my keymap.

I load IntelliJ (14.1.4) and will get this error message:
"Cannot read scheme Default copy.xml  from '$ROOT_CONFIG$/keymaps': Cannot parse first-keystroke: 'alt left'; Action's id=Back; Keymap's name=Default copy"          

When I start using it, my customized  keymap is all gone.