13 July, 2015. Avast blocked the purchased app, Luminar 4, on 2 Macs, both running Mojave 10.4. Avast has posted instructions on exceptions (https://support.avast.com/en-us/article/Antivirus-scan-exclusions)--the instructions do not match the menu choices on Avast. Under Preferences, I had to look at every tab to locate an option to allow Luminar. I contacted Avast (no reply). Now I wonder how many other purchased apps will Avast block? Their list of "trusted" apps is very short.