The App-V 5 client prerequisites were documented in this post
Note that KB2533623 has been superseded by the MS patch KB2758857
If your machine is up to date with patches then when you attempt to install KB2533623 you will receive a message on the lines that it is not required for your system.
If you have a Task Sequence to install KB2533623 and you have injected KB2758857 via offline servicing of the WIM file then remove the step to install otherwise your OSD will error and bomb out.
But when I go to the supercedence info for that patch, it doesn’t list the other KB 😦
Lewis – that’s an old post. If your machine is up to date you can probably skip any KB installs for the client now.