I use Avast antivirus and, yesterday and today, the software stopped my MFP as I tried to open the trigger editor to amend a trigger which was loaded. I had the opportunity of reporting this as a "false positive" but wanted to give Support an opportunity to comment first.
Every time it happens I am forced to restart MFP. My experimentation with triggers is effectively at an end for the time being. I use Avast because I cannot abide Norton or McAfee, and AVG has been amended lately so as to be a complete nuisance.