when you deploy idempiere (or jetty app) to centos.
have some runtime resource go to /tmp folder. See more: Temporary Directories
if long time you don't touch your app, file on "Temporary Directories" can be delete by centos. see more:Centos tmp
so your app will go to break.
it happen here on motive demo server. i install mobile plugin to test long time ago.
now when i go back it said miss some resource file (javascipt, css)
my solution add work folder under jetty home. so temp is manage by jetty not OS.