Free disables itself about every two weeks - issue or marketing ploy?

The past month or so my free version has alerted me that it is disabled and needs to be enabled. Is there an actual issue with it or is it a marketing move to get free users to have to go into the product regularly in hopes of getting upgrades to avoid it?
Anyone?
A quick review didn’t look like this was posted…
Thanks

Repair Avast:

  1. Control Panel → Add/Remove programs → Avast
  2. Click on ‘Repair’.
  3. Follow instructions.
  4. Reboot.