System Extension Blocked

Discussion in 'macOS High Sierra (10.13)' started by Hoff, Mar 9, 2018.

  1. Hoff macrumors member

    Jan 24, 2018
    Hi Hi,

    I'm brand new to Macs. Just got mine this week :)

    I installed the antivirus ESET, which I've used and like a lot on Windows.

    It said "Installation was successful." But I got this message "A program tried to load new system extension(s) signed by ESET... If you want to enable these extensions, open Security & Privacy System Preferences.

    So, did it install ok? Do I need to enable the extensions? Will it run ok if I don't? What is a system extension and what does it mean to enable one?

    Pic attached. Thanks

    Attached Files:

  2. Mike Boreham macrumors 68000

    Aug 10, 2006
    This is not a great feature of High Sierra and causes confusion.

    Did you do what it says? i.e. enable the extension in Security & Privacy System Preferences (General tab). If so you should be OK.

    At one time there was a 30 minute window after the install to do the enable, but not sure if this still applies. If ESET is not working, and you did not enable it in Security and Privacy, you could try reinstalling it which should create the message again.

    I have not tried ESET but I have many of the other AV progs and sooner or later there is an issue, and I end up uninstalling, and I don't run an active AV on my Macs anymore. I have the on-demand ClamXav and Malwarebytes.
  3. KALLT macrumors 601

    Sep 23, 2008
    A system or kernel extension is a kind of plug-in that extends the core of the operating system. It gives much lower-level access to system resources and hardware than a normal program would have. Poorly or maliciously crafted extensions can cause all kinds of problems, which is why you need to be cautious.

    In the current version of macOS you have to explicitly approve such extensions yourself. Whether ESET works without them, I cannot say (I am guessing not).
  4. Hoff thread starter macrumors member

    Jan 24, 2018
    Thanks Mike and KALLT.

    This happened last night. I put the Mac to sleep, and waited to hear back from the forum the next morning. So it's 11 hours later now. Now I go to the General tab of Security & Privacy and don't see any option to "enable these extensions."

    Screenshot attached. Clicking "Advanced" doesn't do it either.

    Attached Files:

  5. BasicGreatGuy Contributor


    Sep 21, 2012
    In the middle of several books.
    Welcome to Mac. :)

    Anti-virus is not really needed on a Mac, as there are no Mac viruses in the wild on OSX. Full-fledged anti-virus programs can sometimes end up slowing down your Mac, and cause more trouble. The free version of Malwarebytes is a much better alternative in my opinion.

    If you want to keep what you have, try running the program. You should get the message pop-up again, click "ok", and you should then be directed to the advanced menu.

    Edited to add: In your screenshot, you didn't click on "ok" on the smaller popup.
  6. Hoff, Mar 10, 2018
    Last edited: Mar 10, 2018

    Hoff thread starter macrumors member

    Jan 24, 2018
    Looks like you might be right Mike, I've lost the ability to enable this extension because I waited too long.

    Found this on the ESET support website:
    ESET system extension blocked in macOS 10.13 (High Sierra)

    Excellent tip. Thank you. Will try re-installing.

    Thank you. Hopefully ESET is trustworthy.

    CORRECTION: restarting the Mac brought up the dialog so I could enable the extension.

    New question: If that extension does cause problems, how to un-enable or remove it? Would uninstalling the ESET software also remove that extension (I hope)?
    --- Post Merged, Mar 10, 2018 ---
    Thank you! Love it here :)

    Thank you. I've read similar things from many people here. But I just wondered - (assuming one gets a virus somehow) - isn't that fixing the problem after it's already occurred (and possibly done some damage) versus an anti-virus like ESET preventing us from getting one to begin with?

    Also I like the personal firewall settings - knowing which software is trying to connect to the web or connect to my computer (and blocking some of them). But I'm not very knowledgable here, so I appreciate everyone's feedback. I'm not set in stone about this. Thanks

    PS: how would I tell if it was my ESET that was causing some slowdown problems?

    PPS: anyone running ESET Cyber Security Pro, and have any feedback good or bad?

    Attached Files:

  7. KALLT macrumors 601

    Sep 23, 2008
    As a rule of thumb: software you install through an installer should be uninstalled through an uninstaller. Alternatively, the vendor should have instructions. This should include a proper removal of the kernel extension also.

    Software you install by drag and drop can generally be moved to trash directly.
  8. Hoff thread starter macrumors member

    Jan 24, 2018

Share This Page

7 March 9, 2018