Hiya ive always had the plugin it just started doing this recently i guess since you changed server but i dont often use it unless a load of channels stop working.
I noticed you said we needed a new plugin so i uninstalled mine and downloaded the one from your blog but i still got the error
So i unistalled that and got the one from your signature and still got the same error so im wondering if something is remaining in my system
if you would prefer to remove the old plugin first
simply ftp to /usr/lib/enigma2/python/Plugins/SystemPlugins and remove the Rat_Updater folder then install the new plugin