Unable to install Avast Security on Mac OS 10.11.6

Downloaded and tried to install several times, but the installer issues an alert at the end of installation, at “Validating Packages” stage: “The installation failed. The installer encountered an error that caused the installation to fail. Contact the software manufacturer for assistance”.
Repaired disk permissions, changed System Preferences to "Allow apps downloaded from Anywhere״, ran DiskWarrior, changed “sudoers” in etc folder to “Read & Write”, changed manually permissions of Applications folder to “Read & Write”, but to no avail. What can be done ?

Maybe a problem with gatekeeper ?

Checked it but the problem still persists. Frustrating. Thank you anyway. I would be happy if someone from Avast could help.

Hello,

we are able to install Avast on 10.11.6, it is a part of our automatic test suite, and this is the first case of someone reporting an error; it is likely this is caused by an interaction with something. Please check your /tmp directory, if there is file similar to “/tmp/avastpostinstall-1569588003-20570.log”, please send the latest to ondrej dot kolacek at avast.com; otherwise I can only suggest checking logs in Console, maybe there is some hint why the installation fails.

Kind regards,
Ondrej Kolacek

Hi,
I was having the same problem on Mojave 10.14

Searching on the web I found a tip to look at the log file on /tmp/avastinstaller_xxxxxx/TEMP_PLUGIN_DIR/vps9.ful

In may case it was saying that firewall on my corporate wifi was blocking the download of the virus definition and the installation failed.

That was the problem, I connected on another network and everything works fine.

I hope this help you.