I have experienced problems since moving to the latest version of one of the IDEA plugins I use. I can download ZIP files of previous versions of the plugin from their website b
Think you can simple drop the jar in the plugins directory:
idea.plugins.path=${user.home}/.IntelliJIdea80/config/plugins
On Windows:
idea.plugins.path=%USERPROFILE%\.IntelliJIdea80\config\plugins