How to disable the "subscription has expired" popup?

The “Your Avast Premium Security subscription has expired” popup (screenshot) pops up like three times a day, and I have found no way to disable it. I tried the Silent Mode but that didn’t work.

It has been causing inconvenience to me. How do I disable it?

Uninstall Avast Premium Security and install Avast Free.

@Asyn, Thank you. I tried uninstalling the premium version, and I was offered with two options: 1) Change to the free version and 2) Uninstall the software. I chose the first option. It should be fine now, hopefully.

You’re welcome.