Avast installation aborted due to incompatible software on Mac Sierra

I had Sophos installed. It was scanning less than 5 items per 30 minutes with time machine. I uninstalled Sophos with the uninstaller and then downloaded Avast. It fails to install due to incompatible software. No forum has a solution for this. I am currently UNPROTECTED and need to get Avast (recommended by my technical support company) working. Solutions? Anyone had similar problem?

Have you checked all folders to see if there is anything from Sophos left ?
Is there still something from Sophos running (could be a service) ?

Have you tried this ? > http://www.macexpertguide.com/how-to-uninstall-sophos-mac-antivirus/

Does sound like something remains of Sophos. To check for a service still running Open Activity Monitor, make sure its set to view all processes (under View Menu). Look for anything related to Sophos still running.

Hi,
Avast checks for the kernel extensions (KEXTs) of the other AVs. So if you get a message, that there
is incompatible SW, there is almost for sure some Sophos kernel extension loaded.