Maybe where paid is not always best?
Avira Antivirus update cripples millions of Windows PCs
Avira has sent out a defective antivirus update that is causing paid versions of its product to block critical Windows
processes and third-party software, effectively rendering millions of PCs unusable.
The good news is that the free edition (Avira AntiVir Personal) does not include ProActiv, so it is not affected.