Hi,
I've encountered the same error as reported by the OP.
I just installed Avast on my Mac for the first time, and got the following:
NOT SECURED
Cannot connect to antivirus engine. Close and re-open the Avast! application to repair the antivirus components.
There is no avastscript*.log file in my /tmp directory, however, there are avastinstscript*.log and avastinstusrscript*.log, so I have included those.
The daemons for Avast seem to be running properly, but the GUI doesn't seem to be able to interact with them.
My /var/log/system shows:
Apr 5 17:44:42 nemesis avast![2413]: av_perform_open: /Library/Application Support/avast/master connect() failed for the 122nd try. No such file or directory [2]
Apr 5 17:45:42 nemesis avast![2413]: av_perform_open: /Library/Application Support/avast/master connect() failed for the 152nd try. No such file or directory [2]
Apr 5 17:46:42 nemesis avast![2413]: av_perform_open: /Library/Application Support/avast/master connect() failed for the 182nd try. No such file or directory [2]
Apr 5 17:47:42 nemesis avast![2413]: av_perform_open: /Library/Application Support/avast/master connect() failed for the 212nd try. No such file or directory [2]
Apr 5 17:48:42 nemesis avast![2413]: av_perform_open: /Library/Application Support/avast/master connect() failed for the 242nd try. No such file or directory [2]
Apr 5 17:49:42 nemesis avast![2413]: av_perform_open: /Library/Application Support/avast/master connect() failed for the 272nd try. No such file or directory [2]
Apr 5 17:50:08 nemesis avast![2602]: av_perform_open: /Library/Application Support/avast/master connect() failed for the 2nd try. No such file or directory [2]
My Mac is running OSX 10.7.3.
Thanks.