Can't complete OS X 10.10.5 software update in App Store I'm trying to update my iMac to OS X 10.10.5, but there seems to be an error when updating.

When I press the update button a message appears to download and restart. When I press it the update starts to install. After some time it get blocked or a message 'show details' is shown, but even after pressing it nothing happens. The update still remains in the App Store.

How can I complete the update?
Assuming you are already on 10.10.something just get the Combo Updater directly from Apple, rather than from the App Store.

Direct link: Download OS X Yosemite 10.10.5 Combo Update