Web access spotty after 2016 security update

Do you have any antivirus software installed on your Mac?

Remove it. Disabling it isn't enough. It's already been confirmed here multiple times in the last few days that it's causing problems.

Antivirus software is completely pointless on a Mac anyway. There are no viruses in the wild that can affect OS X. Adware and Malware, yes, but they require user intervention to be affected by them and antivirus software won't stop them anyway.

Apple didn't break anything. ESET broke your Mac. Uninstall it. Do not reinstall it, or anything like it, ever again.

Your $50+ was wasted on useless garbage. Get over it. Read Effective defenses against malware and other threats.

Apple does not sell ESET antivirus in the mac App store.

It's up to app developers to keep their apps up to date.

According to a press release, "Apple has released OS X El Capitan 10.11.3 for all Mac users, the final version is said to improve the compatibility, security, and stability of OS X and contains bug fixes and security improvements for the Mac operating system. Additionally, Apple has also released security updates for Mac users running OS X Yosemite and OS X Mavericks. Apple recommends that all Mac users install the appropriate updates for their version of OS X."

So from this, I believe that this 10.11.3 update has some features (security updates) in common with those released for Mavericks (10.9).

Meanwhile, ESET knows about your issue and even has a special notification about it here:

http://support.eset.com/alert5781/

While I think you are not using 10.11.3, I suspect that the security update issue you experienced is the same as the one ESET seems to know about. They even suggest several remedies that you can consider.

Anti-virus programs have to burrow into the OS to do their thing and when the OS gets modified or updated, the results can be unpredictable. As apparently happened recently with ESET. I agree with the earlier posters who argue that such programs are not necessary on the Mac. Keep in mind also that malware and phishing programs typically work by tricking you into entering personal data and/or passwords. It's pretty hard to install anything on a modern Mac without entering an administrator's password. If you avoid doing that, or simply use your Mac from a non-administrator account, you've gone a long way towards protecting yourself.

lenf67 wrote:

But I find it rather odd that Apple would do something that renders a certain type of software unusable, while selling said software in their stores and on the App Store.

Apple does not sell "ESET".

"Anti-virus" software serves no beneficial purpose on Macs.

Selling something in the App Store does not mean Apple recommends the software. Apple generally rejects apps if they are known to do illegal things, violate the law of the country the user lives in, or is known to steal customer data, etc... Apple does not reject the app just because it is useless. And as you have shown, software from outside the App Store can be installed regardless of Apple opinion.

As for an Apple employee in an Apple store recommending a product, is meaningless. In a company with more than 1 employee there will be mixed messages happening. One with 100,000+ employees is bound to have lots of mixed messages. Does everyone in your family believe the same things? Is that true when you move to the aunts and uncles, cousins, etc...

The long time forum contributors have seen over and over again the anti-virus, Mac cleaners, and performance enhancing packages have be at the root of system performance problems, the deletion of files that should be left alone, and system panics. This is especially true after an OS X upgrade. Too many people blame the OS X upgrade, and change their mind after removing this class of software.

With respect to anit-virus, please read the following, which is why many of us recommend against anti-virus softare:

How does Mac OS X protect me?

<http://www.thesafemac.com/mmg-builtin/>