For some reason, when I try to update to the latest version of OS X, I go to the app store and it shows the update, when I click update all or install all available software updates it gives me the standard restart notification with the 60 second countdown and the buttons to restart my computer now or later. When I either click restart or just let the timer run down, it then brings a message up saying "Available updates have changed, click view details to view the changes". When I click view details, it just takes me back to the same update page in the app store. There isn't any more details anywhere or another download going on. There is still a button to install, but doing this brings the same "available software updates have change" message.
Rebooting my computer hasn't helped. Any suggestions on how I can get it to update? I'm using a 2012 Macbook Air with OS X 10.10.3.