I just had 2 updates, 1 Flash Player plug-in and a Thunderbird update.
I updated them one at a time and that worked just fine, this is on the latest avast free version 19.8.2393 (build 19.8.4739.541) UI-1.0.415 on my win10 1903 system.
You don't say what avast version/build number you are using or on what OE version.