I have been using Norton Utilities for a number of years.
In the last two months, when I have run the monthly system checks and clean-up, it has wiped one complete folder of work. The folder is a mix of old and new materials, so it is not just very recent work. It only empties that one folder. The folder is in the main body of my work files. It has done this twice. The files are irretrievable, since they are not in trash. They also disappear from my cloud storage (SugarSync).
Why is this and how can I prevent it?