Important: Make sure that you download the YakChat installation file intact, otherwise the installation will fail.
Apple Mac users often have Safari as their default browser. Safari unpacks zip files by default, but the downloaded YakChat installation file must remain unzipped for successful installation into Microsoft Teams.
So before downloading the YakChat installation file, uncheck the Open “safe” files after downloading feature in Safari (as described below), or use another browser, such as Chrome, to download the file without unpacking.