all Avast settings grayed out, and security certificate errors

[REDACTED]

Last week I uninstalled Sophos and switched to Avast. A couple problems:

1: the auto-updaters in Firefox (DevEd) and Steam now complain about invalid security certificates

2: in Avast > Preferences, both Shields tab and Updates tab, all of the checkboxes are grayed out and unclickable. I cannot disable or modify any of the shields, nor can I modify or manually run any updates.

[tumic]

1: the auto-updaters in Firefox (DevEd) and Steam now complain about invalid security certificates

You can add the servers Firefox/Steam are accessing to the excluded servers.

2: in Avast > Preferences, both Shields tab and Updates tab, all of the checkboxes are grayed out and unclickable. I cannot disable or modify any of the shields, nor can I modify or manually run any updates.

That's quite strange. What OS X version do you have? Are there any error messages in the system log?