When trying to update my Mac OS High Sierra to 12.0.2 i receive a message Safari could not be verified err. 311

Disable/Remove problematic applications

If error code 311 happens only when you use specific programs, quite possibly it is the specific program that brings about the error. You can try to log in with different user account to see if the error still occurs when you run the same program. Once you eliminate other possible factors, you will get close to the deep cause of the error.

In the cases when an application get corrupted, outdated, or incompatible with other new installed apps, error message could pop up during the usage, You need to repair, update, or reinstall the app to test if that helps. It is also worth visiting the app developer’s website to see if other users are having the same problem you encounter.

Once you have identified the problematic app which gives arise to error code 311, you could perform a clean uninstallation after backing up related data. To uninstall an application on your Mac, locate its icon the Applications folder from Finder, then drag and drop it to the Trash on the Dock, and empty the Trash to start the removal. As for the possible remnants of the app (like preference files), you can either detect them on your own, or utilize a reliable Mac optimizer to complete the task effectively.

Run disk utility to repair disk permissions

Permission issues can often be responsible for many error codes. In the daily use, fixing those permissions is one of the most common way to resolve problems related to files and applications. If problems happen due to improper permissions, you can use Mac’s built-in Disk Utility to check the startup disk for errors and run a full system permissions fix, so as to ensure the system files are properly accessible. You can also reset the permissions on home folder in your user account, to ensure programs, services and anything else under your account has proper permissions.

Performed a Mac OS X re-installation

Reinstalling Mac OS can be almost seamless. This option will preserve your installed apps, settings, and files, while replace all the core system files with fresh ones. If the error code 311 is caused by corrupted/missing system files, performing a reinstall of Mac OS can be a quick fix for the problems resulting from a damaged operating system. To reinstall Mac OS X, do the followings:

• Make sure to connect your Mac with the Internet, and then restart your Mac.
• Once it reboots and shows a gray screen, hold down Cmd + R keys.
• When you see the OS X Utilities menu, select the Reinstall OS X option.
• Follow the instructions that appear on screen to complete the reinstallation.

In this way your personal files, installed app, and user settings will still be the same as before, and Mac OS X built-in software and system files will be reinstalled. See if this solution helps solve error code 311, or if the problem shows different behavior.

Reset your Mac’s PRAM& SMC to fix hardware issues

Sometimes your Mac will malfunction for no apparent reason. When error code 311 happens and you tried all you know to fix but still end up with failure, you may consider to do a reset. If the error code 311 is hardware-related, the only real hardware-based fix you can do for your Mac is to reset the Parameter RAM (PRAM) or/and system management controller (SMC). It is the first step to solve a wide variety of hardware-related problems. Before resetting PRAM or SMC, you should back up your data or even the whole system on an external drive as a precaution.

PRAM holds information about the configuration of your Mac, including things like startup disk selection, screen resolution, speaker volume, and other control settings. To reset the PRAM, turn off your computer first. Then press the power button, and hold down the Command+Option+P+R keys all the time until your Mac reboots and you hear the startup sound twice, which means you have reset the PRAM.

SMC controls a lot of the physical parts of your Intel-based Mac, like LED indicators, keyboards and other peripherals, cooling fans, and power buttons. How to reset the SMC depends on the type of computer you’re using, so head to Apple's official SMC Reset page, find your model here, and follow their instructions to do a reset.

Check login items to troubleshoot error code 311

In some cases, many issues can be resolved by simply rebooting your Mac, and you can move along. But if the problem persists after a reboot, you can restart your Mac into Safe Mode to do a test. If the error code 311 disappears in Safe Mode, there may be an issue with a startup item, login item, or kext file. You might need to check your login items and see if the error code 311 is related to one of the programs loading up automatically on startup. You can narrow down the scope by doing so:

• To clear out your login items, open System Preferences, and select Users & Groups.
• Click your account on the left, and click the Login Items tab on the right.
• Select the items from the list, and click the minus sight to remove them all.
• Reboot your Mac, and see if the error code 311 shows up or not.

If the issue disappears, that means one of your login items is causing the problem. You can try loading up each of them to test which one causes the problem. If you wanna manage startup items more effectively, use a Mac optimizer to save some trouble.

Delete temporary, junk and cache files

Both system and applications create temporary files, preferences, and caches under your current user account. When some of those files are corrupted, problems may occur including system hangs, app crashes, and the inability to perform specific tasks. To further troubleshoot error code 311, you can log into the Guest account to help determine if the issue is account-based or rooted in the system. If error code 311 persists in your Guest user account, the issue is more likely to be system-wide. But if the error disappears in Guest account, it might be an issue with your home folder.

In the latter case, you can try to clear the cache, temporary and duplicate files for the entire system, to see if this helps. There are three types of cache files you can clean up: user cache, system cache, and browser cache, and there are several ways you can take to manually remove them, but we suggest you to clean them using a Mac optimizer.

Ignore the Download Mac Optimizer stuff, but otherwise good help here...

http://fixmacissue.com/fix-error-code-311-on-mac.html

What is error code 311, and how does it happen?

At times when you are using your Mac as usual, a warning message box might suddenly pop up saying that “The operation can't be completed.An unexpected error occurred (error code 311)”. Troubleshooting that kind of error code could be a tough task if you have no idea what’s happening on your Mac. Error code 311 could happen for a number of reasons, and it may show up with a specific error message:

• mFHBlkDispErr = -311, /*Error occurred during _sDisposePtr (Dispose of FHeader block).*/

The followings are the main causes why your Mac gets error messages:

• Improper operations on the system, application, process or service
• Corrupted system files and directories, misconfigured system settings
• Virus infection, malware or spyware attacks, suspicious file download
• Incompatible or outdated software/hardware installed on the machine
• Junk files filled with the startup drive or current user’s home directory

When you come across the error code 311, there is a general set of troubleshooting steps you can take. Does it happen at regular intervals, or totally random in nature? Does it come out after any changes you made to the system? Is there any app you suspect to be related to this issue?......With these questions in mind, you can do some tests to first verify whether the error is hardware-related, or software-related. Once the root cause of the error are identified, you will be able to fix it successfully by adopting corresponding solutions. Now let’s go straight to figure out what’s going on.

Solutions to fix error code 311 & optimize your Mac:

Here we list several approaches to help you identify and troubleshoot Mac issues. Follow the steps to fix error code 311 and get the tricks to optimize your Mac.

Keep your system and apps up-to-date

Older versions of Mac OS and outdated apps are prone to be attacked by malicious activities. They may also be incompatible with some new features, or insufficient to support certain system operations, and thus drag down your whole Mac performance.

Keeping everything on your Mac updated will not only help the Mac run smoothly, but also lowers the possibility of getting unexpected error, including error code 311. To upgrade your system and apps to the latest version, first go to Apple menu and select App Store. Click on the Updates icon on the top panel, and check the available updates for your system and installed programs. If some apps are not downloaded via the App Store, you will need to check the update manually. For that kind of apps, just launch the app, and access the Software Update option from the Preference settings.