One person tried (1) pressing Update policy and then (2) declining. That seemed to work. I haven't had that problem and so can't confirm that it works.
Please try that and report back. Others have had to resort to a Factory Data Reset.
I am getting it too, but only about a dozen times a day. I went several hours without one today. I'm suspecting some app is misbehaving but only with the update is it finally being detected. Sure would be nice to know what app it is.
I was getting it, caused by my Wifi (another bug in 4.3) and turned off my Wifi, opened the message, went through the process and updated it, and it hasn't come back.