I suggest you stop using it, as it does have serious issues with false positives. Version 2 of Zemana, had much fewer false positives and according to a number of poster, better detection rates too. You can no longer use v2 of Zemana, as it tried to automatically update to v3 and even if you cancel the update, it won't let you run scans.. However, MalwareFox, which is a rebrand of Zemana v2, still works, although there is no free version.
There are links to buy it with a 35% discount, on the following page. The actual giveaway ended long ago.
Before buying it, I would check with them to make sure they have no plans to update to v3. As the whether it is worth buying, that's up to you. If I had a need for a second opinion scanner, I would buy it, but I don't feel I need one at this point in time.