Downloaded 10.10.4. Computer restarted. Got a message saying couldn't verify the installation. Couldn't install. Restarted. Went back to Software Update. It tries to download and install but I get the message "show details" I click it then nothing happens. Software Update shows that I've already installed 10.10.4 on my MBA 5 times (see screen shot where you can see the five or more times 10.10.4 has been "installed"). But my computer is still running 10.10.3. I'm left in limbo. Any ideas to work around this?