Firewall cannot start

Evangeline,
We do understand your concern, mostly this license issue occur due to traces of older AVG. Let's reinstall your AVG Internet Security program to fix the issue.

To uninstall AVG, refer this article: http://avgclick.me/UninstallAVGAV and to install your AVG, go to http://www.avg.com/us-en/download link and download your AVG program.

Once the installation gets completed, restart your device and check for the issue. Thank you.

I recently purchased AVG internet security - unlimited (multiple devices). 
I got 2 error messages:
1. Firewall cannot start due to invalid license.
2. Online shield is not active. 

How do I solve these problems?

Evangeline,
We do understand your concern, mostly this license issue occur due to traces of older AVG. Let's reinstall your AVG Internet Security program to fix the issue.

To uninstall AVG, refer this article: http://avgclick.me/UninstallAVGAV and to install your AVG, go to http://www.avg.com/us-en/download link and download your AVG program.

Once the installation gets completed, restart your device and check for the issue. Thank you.