Author Topic: Installed latest Avast Free for Mac (Nov 30th, '19) and now system hangs at boot  (Read 2588 times)

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Offline cweinstein

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        I'm in a frustrating situation.  Normally problems like these are not difficult for me to figure out but in this case I need some help.

   I spoke to Avast’s first level phone tech support line earlier this evening about this issue but the agent was unable to offer any help to solve the issue and frankly I am not sure that she understood the circumstances of the issue as I described them.  I was told that they simply have few to no support tools to help anyone with their Mac software… which has worried me since all I want is to remove Avast from my system at this point and get it back to normal.

   Here is the chronological rundown:

   I have an Apple 2013+ Mac Pro workstation.  It is updated to Mac OS X Mojave (one operating system back from the very latest that was just released a couple of months ago).  It has had no issues and has been operating normally prior to installing the current Avast Free antivirus software directly from the website.

   The installation software had 2-3 very fast flashes of “installation failed” which quickly went away as the installation continued after each such flash.  And then the installation was finished and appeared to be completed successfully.  The installation software reported this success with a prompt that also informed me that a restart was required for the changes to take effect.

   Additionally, since new Mac OS system security measures were implemented with Mojave I had to enable one system process that Avast wanted.  This tends to be normal when installing new software and especially something like virus scanning software.

   I enabled the process and initiated a restart.  Upon rebooting, the load-up screen took FAR longer than it should have and just when it looks like it would be completed and ready to trigger the GUI….. it just sits there and hangs.  Furthermore the central cooling fan on my Mac Pro does not kick on during all of this.  At one point I realized that no fan cooling was occurring and quickly powered down the system to allow it to cool off.

   There was NO issue with the normal operation of the cooling fan or booting prior to installing Avast Free for Mac.

   I was NOT able to boot into Safe Mode despite multiple attempts.  I WAS however able to boot into Single-User Mode with a command line interface only (no GUI desktop).

   Every attempt to reboot the system normally resulted in a stuck boot sequence that stops before the GUI desktop ever has a chance to load.  And no fan operation, since it seems some system processes are not being allowed to complete yet at boot.


   Before calling Avast’s phone tech support line I scoured the internet for any articles or forum posts describing my specific issue and how to solve it.  All I found were old postings.

   However I did find a couple that appeared relevant to my issue.  An Avast technician replied to this 2014 post on the Avast forum.  He seemed to hint that the issue could be related to Avast’s “File System Shield” function causing the trouble and how to disable it via the command line interface.

        The same technician also showed a way to completely uninstall Avast from the command line interface.

        I tried to do both.  The problem is that since the Avast software code has undoubtedly changed since its 2014 version the exact command line instructions needed to disable File System Shield or completely uninstall from the command line not in line with what I will need to type in 2019 to do the same.


        So my problem is: just after installing the Avast Free for Mac software directly from the Avast website I can no longer boot into a GUI screen on this Mac.  But I CAN boot into the command line interface in Single-User mode.  And I would like to uninstall the Avast software from the command line interface.

     Also, I confirmed that I can manually boot into other secondary external boot SSD drives that I occasionally and the system is working fine with those of course... but my main system SSD in the Mac itself just hangs at boot if I don't opt into Single-User Mode at boot.  And that's the one I need to set right again.

       And yes, I do have a full system backup, albeit a month old but I don't think a full system reinstall over the course of 1.5 days  should be necessary just because I installed Avast's software and am having an issue at startup.


      So with all of that being laid out.... what specific instructions will I need to type into the command line interface in Single-User Mode in order to remove the current/late 2019 Mac OS X based Avast Free software package?

      Or can I boot into another drive and just manually delete every single related file and folder for it in the ~/Library folder?  And if so, specifically which files and folders are the most critical such that they would hamper initial system boot processes?

      All I want is to completely remove Avast and its changes, boot up normally into the GUI and get my machine's main SSD installation back to normal again.

      Currently there is no way for me to use the standard Avast Uninstall function from within OS X’s graphical desktop because directly after installing Avast… I now can no longer boot into the OS X graphical desktop on the main internal SSD.

      Anyone have any insight?

      Thank you in advance and hope at the very least my account helps anyone who has had the same thing happen.


     Here are the only other relevant links I could find in google searches while trying to find a solution to my issue.  All of them are dated by a few years unfortunately. However the "after installing Avast Free my Mac gets stuck at the Apple boot logo" comments are spot-on to my issue:
« Last Edit: December 01, 2019, 11:55:56 AM by cweinstein »

Offline ondrej.kolacek

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Avast AV is loaded by launchd, so it can not impact booting. I sincerely doubt it is the core of your problem.

Saying this, you can run
Code: [Select]
sudo /Applications/ uninstall Avast AV.

Please note this is not an official way how to do this and can be changed at any moment.

Kind regards,
Ondrej Kolacek
« Last Edit: December 02, 2019, 02:05:02 PM by ondrej.kolacek »

Offline cweinstein

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Hello.  Thank you for your reply!  All I can tell you is that my system was working normally with no booting issues until I installed Avast and then rebooted directly after.

I took some screenshots of the machine booting in Verbose Mode which I would be happy to post (much dense text as you'd expect) but to summarize the booting slowed considerably once various "com.avast.xxxxxx" and "com.avast.FileShield" kexts attempted to load but came up with numerous "not found" errors.

However it did finally read "com.avast.FileShield: started".  Yet... this is after all the previous errors that would suggest files are missing.  Also further errors of "Kext com.avast.PacketForwarder not found for unload request".

The specific examples are too numerous to list without posting my picture screenshots.

The final point of boot hanging (again, never happened until I installed Avast from the GUI and then rebooted) is "GTK-RSC" and many addresses after it.

And then: "InstallGTK: GTK installed"

And then the system hangs.


I did try the uninstall command line instructions you posted above and it did work better than the deep into Avast's Application Support folders but it still did not work.

Many numerous error messages of files and kexts not found.

Again, I have pictures of these and would post them here if this did not require hosting them elsewhere.


At this point with another APFS formatted boot drive I will just go in and manually delete every Avast folder that I can locate from my main boot drive and hopefully that will effectively remove Avast from my system and allow me to boot normally.

« Last Edit: December 04, 2019, 06:35:54 AM by cweinstein »

Offline cweinstein

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Well, I stand corrected.  Despite the numerous error messages after having typed in the command you sent the files and folders I was looking for had been removed and it seems that Avast is gone totally aside from one last /Library/Application Support/AvastHUB folder that I had to remove myself.

I initially booted back into my spare APFS boot drive to check everything but I should have just allowed the machine to boot normally into its main drive (onto which Avast was installed).  No more booting issues!  Everything came up normally again and the software was removed.

Thank you Ondrej!!!