I get the same message. I've tried running everything the patcher has to offer as well as reinstalling the game from scratch and nothing works.Worst is, like I said for the first few months of the game I've never had that happen, now I get this glitch and the "Rift could nor install some blah blah blah..run Restore from the patcher as soon as possible".
The sad thing is. I installed Rift on a friends laptop which is an "ok" machine. Everything worked fine. So why is it only some systems have this problem?