App Store - show empty updates

Dear,

I'm new to OS X - I bought Macbook Air 13 mid 2011.

Because a new OS X Yosemite 10.10.4 I see update in App Store but if I click on Updates, there is only button with update all but no name of update. After update all, there is problem with installation of OS X 10.10.4. History is OK.

So question is, Why I dont see names of updates and there is only button with update all?

I tried resetting PRAM.