Q: Update (10.11.6)

Hello Asim.Ali,

Thanks for asking your question here in the Apple Support Communities. I understand how important it is to have the latest and greatest version of OS X, and all the security updates. I would be happy to offer a few things you can check to get your update started.

The error "update can not be verified" is usually caused by a few reasons. The first thing that you want to check is if this is caused by something on the network you are using to try to download the update. Make sure you are using an open wireless network like your home network. If you are connecting to a free wireless network like a school, work, or other business, the airport, a military base, or a hotspot type of a network, this will not work because these types of networks have high security and high traffic. They do not allow the necessary data back and forth causing issues exactly like the one you are currently experiencing. This help article from Apple will assist you with ensuring the necessary requirements are met for the network you are connecting to: Recommended settings for Wi-Fi routers and access points, and this second help article will ensure all the settings are met for updates specifically: Requirements for Software Update Service.

Also, check and make sure you if you are using any third party virus protection, firewalls, or proxies that hide your identity from the internet. These do not have to be set up on the computer, but can also be set up on the router. Some security apps also do this, but are only called Security or VPN. There are literally hundreds of such apps that block incoming ports which will not allow the feature to work. If you are using one of these apps or programs, you may need to check this help article from Apple: Resolve issues between iTunes and third-party security software, or contact the manufacturer or developer to have then help open the necessary ports to allow this feature.

The next thing you want to check once your Mac is connected to the internet properly, is that your Mac is showing the time and date properly, and that those settings are set to update automatically in the Date & Time preferences. This can also be caused if you ever had a repair of the Logic Board or MLB, and the computer was not properly serialized after. Click on the Apple on the menu bar, on the top left of the screen, and click About this Mac. If there is no serial number displayed, you will need to have the Mac re-serialized at the place that did the repair for you.

The last thing I can offer to verify the operating system and update is caused when people use beta or developer versions of the operating system. You will first need to go to the App Store and download the official release of the operating system, then install it. This will remove the unofficial App Store version, and replace it with an App Store official version that can then be updated.

Thanks again for asking your question here. Have a great rest of your day.